Inactivation of cytosolic aspartate aminotransferase accompanying modification of Trp 48 by N‐bromosuccinimide

FEBS Letters

Morino, Yoshimasa¹  Tanase, Sumio¹  Nagashima, Fujio¹ 

[1] Department of Biochemistry, Kumamoto University Medical School, 2-2-1, Honjo, Kumamoto 860, Japan

关键词: Aspartale aminotransferase Substrate induction Conformational change N-Bromosuccinimide Tryptophan residue Interdomain interface;    NBS;    N-bromosuccinimide;    pyridoxal-P;    pyridoxal 5'-phosphate;    HPLC;    high-performance liquid chromatography;   

DOI  :  10.1016/0014-5793(86)80312-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Reaction of N-bromosuccinimide with pig heart cytosolic aspartate aminotransferase led to loss of the enzymatic activity. Chemical analysis indicated the modification of two tryptophan residues. At a low ratio of N-bromosuccinimide to enzyme, oxidation of Trp 122 occurred without affecting the enzymatic activity. Increase in the ratio resulted in the oxidation of Trp 48 with a concomitant decrease in enzyme activity. The modified enzyme did not react with substrates and their analogs. Trp 48 is not within the active site but in the hinge region linking the large domain of the enzyme to the small domain that shows dynamic movement upon binding substrates. The present result suggests that oxidation of Trp 48 may impair the structural integrity of the interdomain interface.

【 授权许可】

Unknown