期刊
EUROPEAN FOOD RESEARCH AND TECHNOLOGY
卷 225, 期 5-6, 页码 637-647出版社
SPRINGER
DOI: 10.1007/s00217-006-0458-y
关键词
hemoglobin; pepsin; protein hydrolysis; enzymatic kinetics; tandem mass spectrometry; circular dichroism
Native bovine hemoglobin was digested with pepsin at pH 4.5 in a batched stirred tank reactor. The resulting peptides in the time-course samples were separated and identified by RP-HPLC coupled with ESI-MS/MS. The secondary structure of bovine hemoglobin was not significantly changed after acid-treatment at pH 4.5 based on far-UV circular dichroism spectra. The alpha-helix contents of peptic hydrolysates decreased gradually with time according to 'Cyone-by-one' mechanism. MS/MS analysis enabled unambiguous identification of 31 and 15 peptides released respectively from alpha-chain and beta-chain, which resulted in their sequence coverage of 100 and 76%. The discrimination of peptic susceptibility between different protein areas was compared in terms of the time-dependent release of peptides. At first, peptic cleavage sites were concentrated around N- and C-terminal regions of alpha-chain and beta-chain. Later, pepsin hydrolyzed the middle part of alpha-chain from N- to C-terminal, while little enzymatic cleavage occurred in the center region of beta-chain due mainly to their high hydrophilic nature. The release kinetics of peptides was discussed in relation to the hydrophobicity of amino acid residues of polypeptide chains.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据