心肝疾病患者血清线粒体天门冬氨酸转氨酶变化及临床意义

ttttt目的ttttt细胞质型天冬氨酸氨基转移酶又称谷草转氨酶，由细胞核GOT1基因编码，催化天冬氨酸的氨基转移到α-酮戊二酸形成草酰乙酸和谷氨酸，在物质代谢调控中起重要作用。本研究以版纳微型猪近交系(Banna mini-pig inbred line, BMI)为材料，克隆GOT1基因，并对其进行生物信息学及组织mRNA表达分析。tttttttttttttttttt方法ttttt利用RT-PCR技术扩增猪GOT1基因，并进行生物信息学分析，同时应用半定量RT-PCR技术明确其mRNA的组织表达特征。tttttttttttttttttt结果ttttt获得了BMI GOT1基因全长1 484 bp的cDNA序列(GenBank登录号：KU705636.1)，包含1 242 bp的开放阅读框。生物信息学分析表明：猪GOT1基因位于14号染色体，包含9个外显子和8个内含子；猪GOT1蛋白无信号肽，无跨膜螺旋，有36个磷酸化位点和1个O连接的糖基化位点，定位于细胞质的概率是94.1%，与水牛、黄牛、黑猩猩、人、食蟹猴、大鼠和小鼠的GOT1蛋白依次有95.6%、95.4%、93.0%、92.7%、92.5%、90.3%和90.1%的同源性；二级结构中以α螺旋为主，无规则卷曲和延伸链含量中等，β转角只在局部出现；三级结构同源建模成功。组织表达分析表明：GOT1 mRNA在检测的15个组织中差异表达，肌肉中表达量最高。tttttttttttttttttt结论ttttt为进一步了解该基因的生理功能及调控机制积累了资料。tttt

X-ray structure refinement and comparison of three forms of mitochondrial aspartate aminotransferase

tttttPurposestttttAspartate aminotransferase, cytoplasmic, also called glutamic-oxaloacetic transaminase 1, is an enzyme that is encoded by the nuclear GOT1 gene. It catalyzes the reversible transamination reaction from L-aspartate and α-ketoglutarate to L-glutamate and oxaloacetate, and plays a crucial role in the metabolic regulation. The aim of this study was to amplify GOT1 gene from Banna mini-pig inbred line (BMI) and to obtain its expression pattern.ttttttttttttttttttMethodstttttThe GOT1 gene was cloned using RT-PCR method from BMI. Nucleotide and protein sequences of GOT1 were utilized to carry out bioinformatics analysis. The semi-quantitive RT-PCR technology was applied to analysis the mRNA expression profiles of tissues.ttttttttttttttttttResultstttttA cDNA of 1 484 bp (GenBank accession No. KU705636.1) of BMI GOT1 was obtained, which contained 1 242 bp opening reading frame. Bioinformatics analysis showed GOT1 gene localized to Sus scrofa chromosomes 14 and consisted of nine exons and eight introns without signal peptide sequences and transmembrane helix. GOT1 protein contained 36 potential phosphorylation sites and 1 O-GlcNAc glycosylation site and to be located in the cytoplasm with 94.1% certainty. The predicted amino acid sequence of the gene has high homology with the water buffalo (95.6%), cattle (95.4%), chimpanzee (93.0%), human (92.7%), cynomolgus monkey (92.5%), rat (90.3%) and mouse (90.1%). The secondary structure of BMI GOT1 was mainly consisted of α-helices, random coils and and extended strands were medium; whereas beta turns were locally present. Its tertiary structure was also constructed by homology modeling. GOT1 mRNA was widely expressed in the 15 tissues of BMI with highest expression level in muscle.ttttttttttttttttttConclusiontttttThe above results will lay a foundation for further study of the gene about its physiological function and regulatory mechanisms in BMI.tttt