Yazar "Akbulut, Ekrem" seçeneğine göre listele
Listeleniyor 1 - 20 / 21
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe A Novel Homozygous TBC1D2B Variant Disrupts Functional Domains and Suggests Impaired Rab-GTPase Regulation in Neurodevelopmental Disorder(Wiley, 2025) Ozturk, Murat; Arslan, Cahide Bulut; Akbulut, Ekrem; Habiloglu, Esra; Yayli, Esra; Uyguner, Zehra OyaRecent reports have linked biallelic loss-of-function variants in the TBC1D2B gene to neurodevelopmental disorder with seizures and gingival overgrowth (NEDSGO) (OMIM 619323), a rare condition characterized by seizures and gingival hyperplasia. However, due to the limited number of reported cases, the phenotypic diversity of this syndrome remains poorly characterized. This study reports four affected children from a consanguineous family in T & uuml;rkiye, in whom a novel variant in this gene was identified. All individuals underwent clinical examination, electroencephalography (EEG), brain magnetic resonance imaging (MRI), histopathological evaluation, and genetic analyses. A novel homozygous truncating variant in the TBC1D2B gene was identified. In silico protein structure modeling was performed to investigate the potential impact of the variant. The identified c.323_324delinsAA; p.(Phe108Ter) variant causes premature protein truncation, resulting in the loss of key functional domains, such as Rab-GAP-TBC, coiled-coil, and PH (pleckstrin homology). All patients exhibited developmental delay (DD), epileptic seizures, gingival fibromatosis, and craniofacial anomalies. The growth delay seen in both of our patients, also described in an earlier case with the same gene variant, suggests that this may be a clinical feature of the syndrome. Binding pocket analysis revealed marked reductions in putative protein interaction regions, suggesting a loss-of-function effect due to the mutation. These findings reveal previously unrecognized aspects of both the genetic and clinical spectrum of NEDSGO syndrome caused by variants in the TBC1D2B gene. The resulting data underscore that disruption of structural protein regions directly contributes to the phenotype of this rare disorder.Öğe Bialelic Pathogenic (c.830G>A(p.R277Q)) Variant Disrupting the GNE Gene Function and Causes Nonaka myopathy Phenotype(Pleiades Publishing Ltd, 2023) Dogan, Mustafa; Akbulut, Ekrem; Gezdirici, Alper; Eroz, Recep; Bozdogan, Sevcan TugNonaka myopathy (MIM 605820) is caused by homozygous pathogenic variants in the GNE gene. It is a recessively inherited early adult-onset myopathy that usually preserves the quadriceps and presents with bilateral foot drop, usually caused by anterior tibialis weakness. In patients with Nonaka myopathy, serum creatine kinases are slightly elevated, muscle weakness progresses slowly, and ambulation loss develops after 15-20 yr. The current study aims to raise awareness of Nonaka myopathy that occurs as a rare phenotype due to pathogenic variants in GNE gene. Detailed family histories and clinical data were recorded. Whole exome sequencing was performed and co-segregation analysis of the family were done by Sanger sequencing. Also the homology model of the mutant protein was created with the ProMod3 algorithm. We identified a bialelic pathogenic variant (c.830G>A) in GNE gene, which explain the patients' clinical status. We present the main findings of two siblings with Nonaka myopathy together with detailed clinical and genetic profiles of the patients together with a three-dimensional mutant GNE protein model. We think that the clinical characteristics and the effect of the (c.830G>A) variant will facilitate our understanding of GNE gene in Nonaka myopathy pathogenesis.Öğe Biallelic novel CCDC186 loss-of-function variant disrupting the gene function causes neurodevelopmental phenotype and review of the literature(Elsevier, 2025) Gezdirici, Alper; Turk, Sultan Buse; Esen, Tuna Eren; Yavas, Cuneyd; Akbulut, Ekrem; Yilmaz, Halil Ibrahim; Dogan, MustafaBackground: Coiled-coil domain-containing protein 186 (CCDC186) is essential for the transport of secretory dense-core vesicles (DCVs), specialized organelles responsible for storing and releasing neurotransmitters and other modulatory molecules in neurons and endocrine cells, thereby playing a crucial role in physiological processes such as synaptic plasticity, neurotransmission, and hormonal regulation. Resent reports have suggested that biallelic loss-of-function (LOF) variants in CCDC186 may be associated with neurodevelopmental disorders and a range of systemic manifestations. Methods: Whole exome sequencing (WES) was performed, and co-segregation analysis of the family was conducted using sanger sequencing. Additionally, five patients with CCDC186-associated phenotypes previously described in the literature were evaluated. Followed by cDNA synthesis and quantitative reverse transcription polymerase chain reaction (qRT-PCR) to analyze gene expression levels. Bioinformatics tools, including RoseTTAFold for protein modeling and STRING for protein-protein interaction networks, were employed to assess the structural and functional consequences of the mutation. Results: We identified a homozygous NM_018017.4:c.535C>T (p.Arg179Ter) nonsense variant in the CCDC186 gene. This variant was associated with a marked downregulation of CCDC186 expression in the proband, with moderate reductions observed in heterozygous family members, suggesting dysregulated gene expression resulting from the mutation. Protein modeling indicated structural alterations, including a shift from intrinsically disordered regions to helix-loop-helix motifs in the mutant protein, as well as reduced binding probabilities for most interacting partners. Conclusion: In this study, we presented the comprehensive clinical and genetic profiles of a Turkish child with a novel CCDC186 variant, along with five previously reported patients from the literature. Our findings support that the homozygous LOF variants of the CCDC186 gene are associated with a novel neurodevelopmental phenotype.Öğe Biallelic Novel USP53 Splicing Variant Disrupting the Gene Function that Causes Cholestasis Phenotype and Review of the Literature(Karger, 2023) Gezdirici, Alper; Sengul, Ozlem Kalaycik; Dogan, Mustafa; Ozguven, Banu Y.; Akbulut, EkremIntroduction: Hereditary cholestasis is a heterogeneous group of liver diseases that mostly show autosomal recessive inheritance. The phenotype of cholestasis is highly variable. Molecular genetic testing offers an useful approach to differentiate different types of cholestasis because some symptoms and findings overlap. Biallelic variants in USP53 have recently been reported in cholestasis phenotype. Methods: In this study, we aimed to characterize clinical findings and biological insights on a novel USP53 splice variant causing cholestasis phenotype and provided a review of the literature. We performed whole-exome sequencing and then confirmed it with Sanger sequencing. In addition, as a result of in silico analyses and cDNA analysis, we showed that the USP53 protein in our patient was shortened. Results: We report a novel splice variant (NM_019050.2:c.238-1G>C) in the USP53 gene via whole-exome sequencing in a patient with cholestasis phenotype. This variant was confirmed by Sanger sequencing and was a result of family segregation analysis; it was found to be in a heterozygous state in the parents and the other healthy elder brother of our patient. According to in silico analyses, the change in the splice region resulted in an increase in the length of exon 2, whereas the stop codon after the additional 3 amino acids (VTF) caused the protein to terminate prematurely. Thus, the mature USP53 protein, consisting of 1,073 amino acids, has been reduced to a small protein of 82 amino acids. Conclusion: We propose a model for the tertiary structure of USP53 for the first time, and together with all these data, we support the association of biallelic variants of the USP53 gene with cholestasis phenotype. We also present a comparison of previously reported patients with USP53-associated cholestasis phenotype to contribute to the literature.Öğe Changes in Interaction Between Accessory Protein 8 and IL-17RA in UK Isolates Caused by Mutations in the SARS-CoV-2 Open Reading Frame 8(İskender AKKURT, 2021) Akbulut, EkremSARS-CoV-2 is the infectous agent of Covid-19, one of the most important health problems of the twenty-first century. IL-17RA is an crucial receptor in the generation of the host immune response. ORF8 is the viral accessory protein of SARS-CoV-2 that suppresses the host immune response. Mutations can alter the viral properties and clinical course of SARS-CoV-2. In this study, we investigated the changes that SARS-CoV-2 ORF8 mutations may cause in the interaction of IL-17RA with ORF8. The study was carried out using 825 complete genome sequences from UK isolates. Mutation analyzes were performed using RDP4 and MEGAX. The protein model was created using the Swiss Model. Protein protein interaction was analyzed by Haddock ver 2.4. Analysis of changes in protein stability was performed using SDM2, mCSM stability and DUET tools. The change in ORF8 - IL-17RA binding affinity before and after the mutation was evaluated using mCSM-PPI2. We detected P30S, R52I, Y73C and L118V mutations in SARS-CoV-2 ORF8. Mutations have been shown to reduce protein stability and affinity. After the mutation, the binding dynamics of ORF8 to IL-17RA were changed. Molecular attachment scores were -78.0±3.4 kcal.mol-1 and -76.3±11.9 kcal.mol-1, for wild type and mutant, respectively. After the mutations, the hydrogen bond number and position between ORF8 and IL-17RA changed. While establishing ten hydrogen bonds between the wild type and IL-17RA, four hydrogen bonds were established between the mutant ORF8 and IL-17RA. The decreased affinity between ORF8 and IL-17RA can be seen as a stronger immune response and a milder clinical course. Although our results contain important data for understanding ORF8, which is an important drug target, it needs to be repeated with in-vivo and crystallgraphy studies.Öğe Clinical Characteristics and Genetic Analyses of Patients with Idiopathic Hypogonadotropic Hypogonadism(Galenos Publ House, 2023) Ciftci, Nurdan; Akinci, Aysehan; Akbulut, Ekrem; Camtosun, Emine; Dundar, Ismail; Dogan, Mustafa; Kayas, LemanObjective: Idiopathic hypogonadotropic hypogonadism (IHH) is classified into two groups-Kalman syndrome and normosmic IHH (nIHH). Half of all cases can be explained by mutations in >50 genes. Targeted gene panel testing with nexrt generation sequencing (NGS) is required for patients without typical phenotypic findings. The aim was to determine the genetic etiologies of patients with IHH using NGS, including 54 IHH-associated genes, and to present protein homology modeling and protein stability analyzes of the detected variations.Methods: Clinical and demographic data of 16 patients (eight female), aged between 11.6-17.8 years, from different families were assessed. All patients were followed up for a diagnosis of nIHH, had normal cranial imaging, were without anterior pituitary hormone deficiency other than gonadotropins, had no sex chromosome anomaly, had no additional disease, and underwent genetic analysis with NGS between the years 2008-2021. Rare variants were classified according to the variant interpretation framework of the American College of Medical Genetics and Genomics (ACMG)/Association for Molecular Pathology. Changes in protein structure caused by variations were modeled using RoseTTAFold and changes in protein stability resulting from variation were analyzed.Results: Half of the 16 had no detectable variation. Three (18.75%) had a homozygous (pathogenic) variant in the GNRHR gene, one (6.25%) had a compound heterozygous [likely pathogenic-variants of uncertain significance (VUS)] variant in PROK2 and four (25%) each had a heterozygous (VUS) variant in HESX1, FGF8, FLRT3 and DMXL2. Protein models showed that variants interpreted as VUS according to ACMG could account for the clinical IHH.Conclusion: The frequency of variation detection was similar to the literature. Modelling showed that the variant in five different genes, interpreted as VUS according to ACMG, could explain the clinical IHH.Öğe Clinical Characteristics and Genetic Analyses of Patients with Idiopathic Hypogonadotropic Hypogonadism (vol 15, pg 160, 2023)(Galenos Publ House, 2023) Ciftci, Nurdan; Akinci, Aysehan; Akbulut, Ekrem; Camtosun, Emine; Dundar, Ismail; Dogan, Mustafa; Kayas, Leman[Abstract Not Available]Öğe Delineating the Adult Phenotype of PGM2L1-Related Neurodevelopmental Disorder(Wiley, 2026) Ercoskun, Pelin; Akbulut, Ekrem; Yavas, Cuneyd; Yilmaz Celik, Lale; Dogan, MustafaPGM2L1 is a crucial enzyme exhibiting glucose 1,6-bisphosphate synthase activity, with predominant expression in brain tissue. In 2021, biallelic pathogenic variants in the PGM2L1 gene were first linked to a neurodevelopmental disorder characterized primarily by developmental delay in four pediatric cases. In this study, we aimed to delineate the adult phenotype associated with the PGM2L1-related neurodevelopmental disorder and to perform functional characterization of the identified variant. Two siblings presenting with neurodevelopmental delay were evaluated clinically and genetically. Exome sequencing of the older sibling revealed a homozygous nonsense variant, c.277C>T p.(Gln73Ter), in the PGM2L1 gene. This variant results in truncation leading to loss of key functional domains including the substrate binding site, catalytic active site, and protein stability regions. Quantitative analysis demonstrated a significant reduction in PGM2L1 gene expression in both siblings compared to controls (p value < 0.01). Unlike previously reported pediatric cases, the second sibling exhibited additional features including scoliosis, renal anomaly, tooth loss, hypothyroidism, bladder trabeculation, anhidrosis, and temperature intolerance, notably in the absence of obesity. These cases represent the first detailed description of an adult phenotype associated with a biallelic pathogenic variant in PGM2L1, expanding the clinical spectrum of this neurodevelopmental disorder.Öğe Effects of Salicylic Acid on Fatty Acid Gene Expression in Carthamus tinctorious L. cv. Dinçer under Pendimethalin Stress(Munzur Üniversitesi, 2020) Akbulut, EkremPendimethalin is a member of the dinitroaniline class herbicide. It used to control most annual grasses and many annual broad-leaved weeds. Salicylic acid acts as an endogenous signal molecule in charge of inducing environmental stress tolerance in plants. Omega-3 fatty acid desaturase is a key enzyme for ?-linolenic acid biosynthesis. Here, we searched to understand the beneficial impacts of salicylic acid on fatty acid desaturase gene (FAD3 and FAD7) expression during pendimethalin stress in safflower (Carthamus tinctorious cv. “Dinçer). In this study, 0.004 and 0.01 M pendimethalin was applied to safflower plants grown under controlled climatic conditions in 36 pots. 0.05 mM salicylic acid was applied to the samples where pendimethalin was applied. After application, gene expression analyze were performed using quantitative polymerase chain reaction. The floor change between the test and control groups was calculated with the formula 2 ^ (delta delta CT). The change between gene expression levels was evaluated by t test (p <0.05). FAD3 and FAD7 expression levels decreased at low pendimethalin concentration. A down-regulation in FAD3 expression was observed in high pendimethalin stress, while an up-regulation in FAD7 expression was detected. Salicylic acid had a ameliorative effect on the negative effect of pendimethalin stress on FAD3 and FAD7 gene expression.Öğe The Effects of SARS CoV-2 nsp13 Mutations on the Structure and Stability of Helicase in Chinese Isolates(İstanbul Üniversitesi / İstanbul University, 2022) Akbulut, EkremObjective: Coronavirus Disease 2019 (COVID19) is a viral disease caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2). The high mutation propensity of the SARS CoV-2 genome is one of the biggest threats to the long-term validity of treatment options. Helicases are anti-viral targets because of the vital role they play in the viral life cycle. In this study, changes in the protein structure caused by SARS CoV-2 nsp13 mutations were investigated to contribute to the development of effective antiviral drugs. Materials and Methods: Genome data of 298 individuals located in the China location were examined. The mutant model was built using deep learning algorithms. Model quality assessment was done with QMEAN. Protein stability analyses were performed with DynaMut2 and Cutoff Scanning Matrix stability. Changes in substrate affinity were performed with Haddock v2.4. Results: In this study, twenty-eight mutations in nsp13 were identified (23 sense, 5 missense). The changes in protein structure caused by the five missense mutations (Leu14Phe, Arg15Ser, Arg21Ser, Leu235Phe, Ala454Thr) were modeled. The mutations caused a decrease in the stability of SARS CoV-2 helicase (-0.99, -1.66, -1.15, -0.54, and -0.73 for Leu14Phe, Arg15Ser, Arg21Ser, Leu235Phe, Ala454Thr, respectively). The mutations reduced the helicase's affinity to the substrate. The docking scores for wild-type and mutant helicase were -84.4±1.4 kcal.mol-1 and -71.1±6.7 kcal.mol-1, respectively. Conclusion: Helicase mutations caused a decrease in the protein stability and nucleic acid affinity of the SARS CoV-2 helicase. The results provide important data on the development of potential antivirals and the effect of mutation on the functions of viral proteins.Öğe Endoplasmic reticulum aminopeptidase-1 polymorphism increases the risk of rheumatoid arthritis(2022) Akbulut, Ekrem; Yıldırım, Tülay; Öztürk, OnurObjectives: Endoplasmic reticulum aminopeptidase-1 (ERAP1) polymorphic changes cause autoimmunity. To understand the contribution of ERAP1 to the occurrence of rheumatoid arthritis (RA) disease, we investigated the relationship between ERAP1 and RA. Methods: This study was conducted with 201 patients and 171 healthy controls. The rs26653, rs27044, rs27582, rs28096, and rs30187 polymorphic regions of ERAP1 were investigated. The comparison was done with Arlequin software and logistic regression. Haplotypes were analyzed with Phylogenetic Network software. ERAP1 was modeled using Promod3. Topological changes in ERAP1were analyzed with TM-Score. Results: The results showed that rs26653G>C (p=0.002, OR=2.001, 95%CI=1.276–3.137), rs27044C>G (p=0.037, OR=1.583, 95%CI=1.028–2.440), rs27582G>A (p<0.05, OR=0.348, 95%CI=0.194–0.622) and rs30187C>T (p=0.006, OR=1.849, 95%CI=1.191–2.870) polymorphisms are associated with RA disease risk. The relationship between rs28096 polymorphism and RA disease risk could not be determined (p=0.509). The risk haplotype for rheumatoid arthritis was determined as [CGAAT]. It was determined that polymorphisms of ERAP1 cause changes in the entry pocket of substrate and ligand. Conclusions: We report a haplotype [CGAAT] that is associated with RA risk from Turkey that has not been described before. These data will make important contributions to elucidating the molecular mechanism of RA.Öğe Functional evaluation of NAA10 variants in patients with Ogden syndrome(Lippincott Williams & Wilkins, 2026) Aydin Gumus, Aydeniz; Dogan, Mustafa; Gezdirici, Alper; Akbulut, Ekrem; Kinay Ermis, DuyguObjectives The catalytic subunit of NatA, the main component of the N-terminal acetyltransferase complex, which is involved in most of the acetylation of the human proteome, is encoded by the NAA10 gene. Mutations in the NAA10 gene lead to neurodegenerative diseases associated with disruption of acetylation. Ogden syndrome (OS) is a rare X-linked recessive or dominantly inherited disorder associated with NAA10 gene mutations, characterized by variable findings such as autism spectrum disorder, intellectual disability, and cardiac anomalies. In this article, it is aimed to clarify the functionality of two novel NAA10 gene variants in two female patients with OS. Methods A whole-exome sequencing (WES) study was performed from the blood samples of the patients. The effects of the two variants found by tertiary structure modeling, protein stability analysis, and molecular docking analyses on NAA10 were examined. Results Autism, intellectual retardation, and epilepsy were prominent in the patients, and heterozygous variants c.346C>T and c.439A>T in the NAA10 gene were detected in WES. The clinical findings were compatible with OS. The p.Arg116Trp and p.Met147Leu changes in the NAA10 gene caused changes in the overall topological structure of NAA10, including the substrate and ligand binding site. Conclusion In this study, c.346C>T and c.439A>T variants were found to alter the functional stability, structure, and energy of NAA10. Functional analyses of NAA10 variants in two rare OS patients have once again demonstrated that novel variants are essential studies for phenotype-genotype correlation association steps.Öğe Investigation of changes in protein stability and substrate affinity of 3CL-protease of SARS-CoV-2 caused by mutations(Sociedade Brasileira de Genetica, 2022) Akbulut, Ekrem3CLpro of SARS-CoV-2 is one of the enzymes required for the replication process of the virus responsible for the COVID-19 pandemic. In this study, changes in protein stability and substrate affinity caused by mutations were investigated to stir the development of potent inhibitors. Sequence data of samples were obtained from the NCBI Virus database. Mutation analyses were performed with RDP4 and MegaX. 3CLpro tertiary models were created using Robetta. Molecular docking for peptidomimetic substrate and inhibitor ligand was done with Autodock v4.2 and Haddock v2.4. Protein stability analysis was performed using mCSM stability and DynaMut2. Twenty-four missense mutations in 3CLpro were identified in this study. Changes in the 3CLpro structure induced by the mutations Met49Thr, Leu167Ser, and Val202Ala resulted in significant levels of instability (-2.029,-2.612,-2.177 kcal.mol-1, respectively). The lowest interaction energy for substrate was-58.7 kcal.mol-1 and-62.6 kcal.mol-1 in wild-type and mutant, respectively. The lowest docking energy for ligand was-6.19 and-9.52 kcal.mol-1 for wild-type and mutant, respectively. This study reports for the first time that mutations cause increased substrate affinity of 3CLpro from SARS-CoV-2. This research provides important data for the development of potent peptidomimetic inhibitors for the treatment of COVID-19.Öğe Mutations in the SARS CoV-2 spike protein may cause functional changes in the protein quaternary structure(Turkish Journal of Biochemistry, 2021) Akbulut, EkremObjectives: This study aimed to model the changes resulting from mutations in surface (spike/S) glycoproteins, which play a key role in the entry of the severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) into host cells, in a protein quaternary structure and to evaluate their possible effects on the functional structure. Methods: Genome sequence information of SARS CoV-2-infected patients located in Turkey was obtained from the GISAID EpiCoV database. Structural analysis of spike proteins was done using bioinformatics tools (MAFFT, PSIPRED, ProMod3, PyMoL and DynOmics). Results: We identified 76 Thr>Ile mutations in the N-terminal domain; 468 Ile>Val mutations in the receptor binding site and 614 Asp>Gly, 679 Asn>Lys, 771 Ala>Val and 772 Val>Ile mutations in the S1 subunit. It has been observed that the mutations, except those of residues 771 and 772, may cause significant conformational, topological and electrostatic changes in a protein quaternary structure. It has been determined that the mutations in the receptor binding site transform the protein structure into a formation that can mask the binding site and affect receptor affinity. Conclusions: It has been considered that SARS CoV-2 S glycoprotein mutations may cause changes in a protein functional structure that can affect the severity of disease.Öğe Novel biallelic nonsense mutation in IGHMBP2 gene linked to neuropathy (CMT2S): A comprehensive clinical, genetic and bioinformatic analysis of a Turkish patient with literature review(Elsevier, 2025) Yavas, Cuneyd; Dogan, Mustafa; Ozgor, Bilge; Akbulut, Ekrem; Eroz, RecepBackground: Spinal muscular atrophy with respiratory distress type 1 (SMARD1) and Charcot-Marie-Tooth type 2S (CMT2S) typically present before age 10. Genetic factors account for up to 50 % of neuropathies, which often display varied symptoms. Mutations in the IGHMBP2 gene are associated with both CMT2S and SMARD1, resulting in a rare clinical condition marked by axonal neuropathy, spinal muscular atrophy, respiratory distress, and muscle weakness. Method: Detailed family histories and medical data were collected. Segregation analysis was performed using Sanger sequencing and whole exome sequencing. Additionally, a review of molecularly confirmed patients was conducted. Protein tertiary structures expressed in the IGHMBP2 gene were tested for topological and conformational changes using modeling programs and in-silico tools. Results: We identified a novel homozygous nonsense mutation (c.2568_2569del p.Gly857Alafs*27) in a family with a member showing neuropathy. This report details the clinical and genetic findings of the affected individuals, including a Turkish patient with neuropathy, and compares them with literature cases. Conclusion: Understanding the clinical impact of the (c.2568_2569del p.Gly857Alafs*27) mutation will enhance our knowledge of IGHMBP2 gene defects role in neuropathy. This study aims to highlight this severe recessive disease caused by pathogenic IGHMBP2 gene mutations and to examine the mutation spectrum and phenotype differences.Öğe Pendimethalin ve Salisilik Asit Uygulamalarının Carthamus tinctorius L. cv. “Remzibey” Yağ Asidi Desatüraz Genlerinin Anlatımı Üzerine Etkisi(Iğdır Üniversitesi, 2020) Akbulut, EkremAspir (Carthamus tinctorius L.), tohumlarında yüksek kaliteye sahip doymamış yağ asitlerinden oleikasit ve ?-linolenik asit içeren endüstriyel hammadde kaynağı olma özelliğine sahip önemli bir yağ bitkisidir.Pendimethalin yabancı ot kontrolünün sağlanması için ekonomik değere sahip bitkilere uygulanan dinitroanilingrubu bir herbisittir. Salisilik asit biyotik ve abiyotik streslere karşı bitki savunmasında yer alan önemli bir bitkiselhormondur. Omega-3 yağ asidi desatürazlar (FAD3 ve FAD7) ?-linolenik asit biyosentezi için anahtarenzimlerdir. Bu çalışmada pendimethalin ve salisilik asitin yağ asidi metabolizmasında görev alan FAD3 ve FAD7gen anlatım düzeyleri üzerindeki olası etkileri araştırılmıştır. Çalışmada toplam 36 saksıda kontrollü iklimşartlarında yetiştirilen aspir bitkilerine 0,004 ve 0,01 M pendimethalin uygulaması yapılmıştır. Pendimethalinuygulanan örneklere 0,05 mM salisilik asit uygulanmıştır. Uygulama sonrası RNA izolasyonu, cDNA sentezi vekantitatif polimeraz zincir reaksiyonu gerçekleştirilmiştir. Test ve kontrol grupları arasındaki kat değişimi 2^ (-delta delta CT) formülü ile hesaplanmıştır. Gen anlatım düzeyleri arasındaki değişim t testi ile değerlendirildi(p<0,05). Pendimethalinin FAD3 ve FAD7 genlerini aşağı yönde regüle ettiği, artan pendimethalinkonsantrasyonuna bağlı olarak gen anlatım düzeylerinin azaldığı belirlenmiştir. Salisilik asitin pendimethalininortaya çıkardığı toksik etkiyi azaltıcı yönde etki gösterdiği, FAD3 ve FAD7 genlerini yukarı yönlü regüle ettiğitespit edilmiştir. Pendimethalinin Carthamus tinctorius L. Remzibey çeşidinde yağ asidi kalitesi ve ?-linolenikasit biyosentezinde azalmaya neden olabileceği, salisilik asitin ise pendimethalinin olumsuz etkilerini gidericietkiye sahip olduğu ve ?-linolenik asit miktarında kısmi artışa katkı sunabileceği düşünülmektedir.Öğe The role of A268V exon-7 polymorphism of PPARA in development of axial spondyloarthritis(WALTER DE GRUYTER GMBHGENTHINER STRASSE 13, D-10785 BERLIN, GERMANY, 2021) Akbulut, Ekrem; Yolbas, S; Ozgen, MObjectives: Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that mainly affects the axial skeleton. Peroxisome proliferator activated receptor alpha (PPARA) is an intracellular transcription factor, which play a role in inflammation and osteoblasting activity. This study is designed to investigate the relationship of NG_012204.2:p.A1a268Val polymorphism of PPARA with axSpA risk and its role in disease development. Methods: This study was conducted with 168 patients and 181 controls. Genotyping was done with MALDITOF. Gene expression level was analyzed by quantitative real time PCR (RT-qPCR). The protein homology models of PPARA were created with ProMod3. Ligand binding dynamics were tested using the AutoDock4 docking program. Statistical evaluations were made with SPSS (ver24) and GeneGlobe. Results: Our results showed that C>T polymorphism causing NG_012204.2:p.A1a268Val change was associated with disease risk (p=0.024) and T allele increased disease risk 1.7 times (95% CI=1.070-2.594). PPARA expression decreased (p<0.05) in individuals carrying the T allele. We determined that the ligand entry pocket was opened 1.1 A in the polymorphic PPARA. Polymorphic change caused a decrease in the ligand binding affinity. Conclusions: Our results provide an important contribution to elucidating the development of axSpA and demonstrate the potential of PPARA as a marker for the diagnosis of axSpA.Öğe SARS CoV-2 nsp1 Mutasyonlarının Protein Yapıda Ortaya Çıkardığı Değişimler(Munzur Üniversitesi, 2020) Akbulut, EkremŞiddetli akut solunum yolu sendromu koronavirüsü 2 (SARS CoV-2) pozitif polariteli ve tek iplikli bir RNA virüsüdür. Virüsün sebep olduğu COVID19 hastalığı on ay gibi kısa bir sürede 900 binden fazla insanın ölümüne neden oldu. Virüs ile mücadelede etkin ve spesifik bir ilaç ve aşı henüz bulunmamaktadır. İlaç ve aşı geliştirme çalışmaları virüsün yapısal ve fonksiyonel özelliklerinin kapsamlı bir şekilde anlaşılmasını gerekli kılmaktadır. Hızlı yayılım gösteren virüsün yüksek mutasyon hızı geliştirilecek aşı ve ilaçların etkinliklerini sürdürebilmelerinin önündeki en büyük engellerden biridir. Hücresel boyutta viral enfeksiyonun başlangıcında yer alan SARS CoV-2 yapısal olmayan protein 1 (nsp1) önleyici tedavi için potansiyel hedef proteindir. Konak hücre translasyonunu engelleyen nsp1’in yapısının bilinmesi önemlidir. Bu çalışmada 222 Avrupa izolatında görülen nsp1 mutasyonlarının protein yapıda ortaya çıkarabileceği değişimler yapay zekâ tabanlı bir modelleme yazılımı olan trRosetta kullanılarak modellenmiştir. NCBI Virüs veritabanından elde edilen dizi bilgileri MAFFT çoklu dizi hizalama programı ile hizalanmıştır. Mutasyon analizleri RDP4 yazılımı ile yapılmıştır. Mutant protein primer yapı MegaX yazılımı ile oluşturulmuştur. Protein kalite skorları QMEAN algoritması kullanılarak analiz edilmiştir. Proteinleri fizikokimyasla özellikleri ProtParam ExPAsy programı ile yapılmıştır. Elde edilen protein yapıların konformasyonel analizleri PyMOL ile yapılmıştır. SARS CoV-2 Avrupa izolatlarında görülen nsp1 mutasyonlarının protein sekonder ve tersiyer yapısında konformasyonel ve topolojik değişimlere neden olabileceği tespit edilmiştir. SARS CoV-2 katalitik bölgeyi içine alan P153 ve N178 rezidüleri arasında kalan bölgede görülen değişimin proteinin fonksiyonel özelliklerini etkileyebileceği düşünülmektedir. Elde edilen verilerin önleyici ve tedavi edici yaklaşımlara önemli veriler sunabileceği düşünülmektedir.Öğe SARS CoV-2 Spike glycoprotein mutations and changes in protein structure(Trakya Üniversitesi, 2021) Akbulut, EkremSevere Acute Respiratory Syndrome Corona Virus-2 (SARS CoV-2) is a single-stranded positive polarity RNA virus with a high virulence effect. Spike (S) glycoprotein is the outermost component of the SARS CoV-2 virion and is important in the entry of the virus into the cell via the angiotensin converting enzyme 2 (ACE2) receptor. ACE2 plays an important role in the regulation of human blood pressure by converting the vasoconstrictor angiotensin 2 to the vasodilator angiotensin 1-7. In this study, the changes that mutations in Asian isolates may cause in S glycoprotein structure were analyzed and modeled to contribute to drug and vaccine targeting studies. Genome, proteome and mutation analyses were done using bioinformatics tools (MAFFT, MegaX, PSIPRED, MolProbity, PyMoL). Protein modelling was performed using ProMod3. We detected 26 mutations in the S glycoprotein. The changes that these mutations reveal in the general topological and conformational structure of the S glycoprotein may affect the virulence features of SARS CoV-2. It was determined that mutations converted the receptor binding domain (RBD) from down-formation to like-up formation. It is thought that conformational change occurring after mutation in RBD may cause an increase in receptor affinity. These findings could be beneficial for disease prevention of and drug/vaccine development for SARS CoV-2.Öğe SARS-CoV-2 Spike Protein XBB.1.5 Mutations Altered Four Conserved Antigenic Determinants(Mdpi, 2026) Akbulut, Ekrem; Yildirim, Meltem; Kahraman, HuseyinThe continuous evolution of SARS-CoV-2 affects its infectivity and ability to evade the immune system. The XBB.1.5 subvariant carries numerous mutations compared to previous Omicron variants and exhibits significant evasion of polyclonal neutralizing antibodies. In this study, the mechanistic effects of mutations in the XBB.1.5 spike protein on structural stability, antigenic markers, and antibody epitopes were analyzed using homology modeling, epitope prediction, protein stability analysis, coarse-grained dynamic simulations, and chain-specific interface mapping. Thirty-eight amino acid substitutions were identified relative to Wuhan-Hu-1, including 22 in the receptor-binding region. The prefusion trimeric fold was conserved, with localized rearrangements in the N-terminal domain, receptor-binding domain, and S1/S2 region. Linear B-cell epitope prediction yielded similar epitope counts and length distributions in wild-type and XBB.1.5, but only moderate residue-level overlap (Jaccard approximate to 0.40-0.62), indicating epitope turnover and alteration of four conserved antigenic determinants. Functional screening suggested that similar to 45% of substitutions could affect protein function. Chain-specific interface analysis of the A-B protomer interface indicated preserved inter-protomer coupling with modest repacking of the polar/directional contacts. Overall, XBB.1.5 appears to maintain ACE2 engagement while redistributing antibody targets, underscoring the need for updated vaccine formulations and therapeutic antibodies.
