Egg white avidin. II. Isolation, composition, and amino acid sequences of the tryptic peptides.
Egg white avidin. II. Isolation, composition, and amino acid sequences of the tryptic peptides.
复制标题
蛋清亲和素。
DOI：
--
复制
发表时间：
1971
影响因子：
4.8
通讯作者：
R. Delange
中科院分区：
文献类型：
--
作者：
T. S. Huang;R. Delange
从还原和羧甲基化的蛋清亲和素的胰蛋白酶水解物中，通过对Dowex 50-X2梯度洗脱得到的部分进一步纯化，分离出16个主要肽，范围从2到17个残基。这16个肽的组合组成，加上从胰蛋白酶水解物中分离的游离赖氨酸，共有128个残基，与氨基酸分析确定的亲和素亚基的组成一致。确定了这些肽的完整氨基酸序列，并研究了其他肽的序列，这些肽是由二次切割产生的。通过对同一肽的两种形式（一种形式含nh2末端苏氨酸，另一种形式含nh2末端异亮氨酸）的近似等量分离，确定了序列在一个位置上存在异质性。对亲和素和唯一发现含有碳水化合物的色氨酸进行碳水化合物分析，发现它们各含有4个氨基葡萄糖残基和5个甘露糖残基。
Abstract From a tryptic hydrolysate of reduced and carboxymethylated egg white avidin, 16 major peptides, ranging from 2 to 17 residues, were isolated by further purification of the fractions obtained by gradient elution from Dowex 50-X2. The combined compositions of these 16 peptides, together with free lysine which was also isolated from the tryptic hydrolysate, account for 128 residues in agreement with the composition of the subunit of avidin, determined by amino acid analysis. The complete amino acid sequences of these peptides were determined, and the sequences of other peptides, resulting from secondary cleavage, were also investigated. The presence of heterogeneity in the sequence at one position was established by the isolation in approximately equal yield of two forms of the same peptide, one form with NH2-terminal threonine, and the other form with NH2-terminal isoleucine. Carbohydrate analyses of avidin and the only tryptic peptide found to contain carbohydrate gave 4 residues of glucosamine and 5 residues of mannose in each.