Carboxy-terminal amino acid sequence of a human fibrinogen gamma-chain variant (gamma').
Carboxy-terminal amino acid sequence of a human fibrinogen gamma-chain variant (gamma').
复制标题
人纤维蛋白原γ链变体（γ）的羧基末端氨基酸序列。
作者：
C. Wolfenstein‐Todel;M. Mosesson
一个正常的人纤维蛋白原伽马链变异体，称为伽马‘，由于延长的COOH-末端序列，比伽马链(51500比49500)大。用高压液相色谱分离得到扩展的羧基溴化氰多肽(CNBre‘)，并测定了其氨基酸序列。与相应的羧基末端伽马链肽(CNBre)的比较表明，伽马链的最后4个氨基酸被富含天冬氨酸和谷氨酸的20个残基取代，序列为Val-Tyr-Pro-Glu-His-Pro-Ala-Glx-Thr-Glx-Tyr-Asx-Ser-Leu-Arg-Pro-Glx-Asx-Asx-Leu。来自先天性功能失调的纤维蛋白原分子(纤维蛋白原paris 1)的突变伽马链(Gamma Paris I)同时表现出Gamma和Gamma‘特征，这表明Gamma和Gamma’链都是由单个基因产生的。如果这一建议是正确的，那么观察到的氨基酸序列的差异可以用伽马链和伽马链的不同mRNAs的存在来解释，这两条链分别是通过差异RNA剪接从一个基因转录而来的。
A normal human fibrinogen gamma-chain variant, termed gamma', is larger than the gamma chain (51 500 vs. 49 500) due to an extended COOH-terminal sequence. The extended COOH-terminal cyanogen bromide peptide (CNBr e') was isolated by high-pressure liquid chromatography, and its amino acid sequence was determined. Comparison with the corresponding COOH-terminal gamma-chain peptide (CNBr e) showed that the last four amino acids of the gamma chain were replaced in gamma' chains by a 20-residue fragment rich in aspartic and glutamic acids, having the sequence Val-Tyr-Pro-Glu-His-Pro-Ala-Glx-Thr-Glx-Tyr-Asx-Ser-Leu-Arg-Pro-Glx-Asx-Asx-Leu . Mutant gamma chains (gamma Paris I) from a congenitally dysfunctional fibrinogen molecule (fibrinogen Paris 1) express both gamma and gamma' features, suggesting that both gamma and gamma' chains are produced from a single gene. If this suggestion is correct, the observed differences in amino acid sequence could be explained by the existence of different mRNAs for gamma and gamma' chains, respectively, which are transcribed from one gene by differential RNA splicing.