Egorov Ts A, Kazakov V K, Musoliamov A Kh, Pustobaev V N, Kovaleva G K
Bioorg Khim. 1993 Dec;19(12):1158-68.
By means of covalent chromatography on thiopropyl-sepharose 6B the N-terminal, as well as other tryptic cysteine-containing peptides of the bovine tryptophanyl-tRNA-synthetase (EC 6.1.1.2) were purified and characterized, their structures being determined by a combination of plasma desorption mass spectrometry and peptide sequencing. In total, six different peptides containing seven cysteine residues were analysed. The N-terminal amino acid (presumably, alanine) was shown to be acetylated in the nature enzyme amino acid sequences of some cysteine-containing peptides proved to differ from those deduced from the cDNA structure, thus indicating the presence of the enzyme's isoforms. The purification does not affect the peptides' sulfhydryl groups. The number of cysteine residues in the peptides could be determined with a high accuracy by measuring their masses before and after alkylation with 4-vinylpyridine.
通过在硫丙基琼脂糖6B上进行共价色谱法，对牛色氨酰 - tRNA合成酶（EC 6.1.1.2）的N端以及其他含胰蛋白酶切割半胱氨酸的肽段进行了纯化和表征，其结构通过等离子体解吸质谱和肽测序相结合的方法确定。总共分析了六种含有七个半胱氨酸残基的不同肽段。N端氨基酸（推测为丙氨酸）在天然酶中被证明是乙酰化的，一些含半胱氨酸肽段的氨基酸序列与从cDNA结构推导的序列不同，从而表明存在该酶的同工型。纯化过程不影响肽段的巯基。通过测量肽段在用4 - 乙烯基吡啶烷基化前后的质量，可以高精度地确定肽段中半胱氨酸残基的数量。
