摘要
为进一步研究山羊胰岛素样生长因子结合蛋白1(insulin-like growth factor-binding proteins 1,IGFBP-1)基因的蛋白表达及生理功能,根据已测定出的山羊肝脏组织的IGFBP-1基因全编码区序列,并结合从NCBI获取的19个物种相应序列,利用ExPasy、NetPhos、NetOGlyc、SignalP等生物软件分析IGFBP-1基因CDS区及其氨基酸的理化性质、结构特点。结果显示,山羊IGFBP-1基因的CDS全长编码的多肽含有263个氨基酸残基,理论pI=6.33,分子质量为28.5758ku,非稳定系数为53.15,非球形且定位于细胞外。IGFBF-1起始25个氨基酸残基构成信号肽,成熟肽具有2个疏水区、4个亲水区,无跨膜区;二级结构以无规卷曲为主,α-螺旋和延伸片段很少。预测存在磷酸化(17个)和O-糖基化(8个)两种翻译后修饰,但后者分值较低。山羊IGFBP-1核苷酸、氨基酸序列相似性与绵羊和牛的分别为99%和98%,与其他哺乳动物间的相似性也较高。进一步分析发现,IGFBP-1N-端(26-110)和C-端(204-263)的保守性均在50%以上;信号肽(1-25)和中间连接区(111-203)则变异很大,山羊和绵羊的中间区序列完全一致,但与人的相似性只有9%。除RGD和YF在斑马鱼和鸡中不一致外,其他基序包括新片段(FYLPNC)在物种中高度保守。山羊IGFBP-1是一种稳定性较差、弱亲水性且具有信号肽的分泌蛋白,在物种间高度保守,磷酸化是调控其功能的主要因素。
In order to reveal the construction features of goat insulin-like growth factor-binding proteins 1 （GFBP-1） IG FBP 1 in the molecular level and provide a theoretical basis for further study on its protein expression and physical function in goat. Sequence of IGFBP-1 CDS from liver of newborn Nanjiang Mongolian Grazelle, and of other 19 species from NCBI, were analyzed using biology softwares, including ExPasy, NetPhos, NetOGlyc and SignalP. The complete coding region of goat IG- FBP-1 encoded 263 amino acid residues. The theory value of IGFBP-1 pI and Mw was 6.33 and 28. 5758 ku, respectively. IG FBP 1 was not a globular protein and the instability index （II） amounted to 53.15, and localized extracellularly. The first 25 amino acid residues formed signal peptide, and there were two hydrophilic regions and four hydrophobic regions in primary se- quence of goat IGFBP-1, but no transmembrane helices existed in mature protein. Followed by alpha helix and extended strand, random coil was most popular in the secondary structure. 17 phosphorylation sites （11 Ser sites） and eight o-glycosyla- tion sites （7 Thr sites） were predicted, however, the latter had low confident score. The nucleotide and amino acid sequences of IGFBP 1 gene in different species were highly conservative, there were 99~ and 98~ homology with sheep and bovine at both levels. Further studies showed that the N-terminal domain（26--110） or the C-terminal domain（204--263） of IGFBP-1 shared similarity more than 50~ among species, however, the signal peptide（1--25） and midregion（111--203） varied dramat- ically, for exampte, goat had the same linked region with sheep, while shared 9 ~ similarity with human. Several motifs inclu- ding a new segment （FYLPNC） were consistency among 20 species too, while RGD and YF had variants in zebrafish and chick- en. The results indicated that IGFBP-1 of goat was an unstable, weakly hydrophilic secretory protein with signal peptide, whose conservation was high among species and not glyco
出处
《中国畜牧兽医》
CAS
北大核心
2012年第5期20-26,共7页
China Animal Husbandry & Veterinary Medicine
基金
国家级大学生创新性实验项目(091062609)
四川省教育厅重点项目(09ZA073)
四川省科技支撑计划(2011NZ0003)
