Williams J
Biochem J. 1982 Mar 1;201(3):647-51. doi: 10.1042/bj2010647.
Tetranitromethane reacts with essentially all 21 tyrosine residues of iron-free ovotransferrin. In iron-ovotransferrin, 7 mol of tyrosine/mol of protein are unreactive. Peptides containing the unreactive tyrosine residues were isolated from digests of nitrated iron-ovotransferrin. By comparing the structures of the peptides with the amino acid sequence of ovotransferrin it is found that there are ten protected residues occupying positions 42, 82, 92, 188, 319, 415, 431, 521 and 524 in the polypeptide chain. The problem of identifying the tyrosine residues that form bonds with the metal atoms is discussed.
四硝基甲烷与去铁卵转铁蛋白的所有21个酪氨酸残基基本上都能发生反应。在铁结合型卵转铁蛋白中,每摩尔蛋白质有7摩尔酪氨酸不发生反应。从硝化的铁结合型卵转铁蛋白的消化产物中分离出了含有这些不反应酪氨酸残基的肽段。通过将这些肽段的结构与卵转铁蛋白的氨基酸序列进行比较,发现多肽链中有10个受保护的残基,位于第42、82、92、188、319、415、431、521和524位。文中讨论了鉴定与金属原子形成键的酪氨酸残基的问题。