Different phosphate binding modes of Streptomyces griseus aminopeptidase between crystal and solution states and the status of zinc‐bound water

FEBS Letters

Harris, Michael N¹  Ming, Li-June¹ 

[1] Department of Chemistry and Institute for Biomolecular Science, University of South Florida, Tampa, FL 33620-5250, USA

关键词: Aminopeptidase;    Dinuclear;    Fluoride;    Inhibition;    Phosphate;    Streptomyces;   

DOI  :  10.1016/S0014-5793(99)00879-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Phosphate shows a non-competitive inhibition toward a Streptomyces aminopeptidase (sAP) between pH 5.85 (K _i=0.48 mM) and 9.0 (110 mM), with a pK _a of 7.1 likely due to ionization of H₂PO₄ ⁻. This non-competitive inhibition pattern indicates that phosphate binding to sAP in solution is different from that in the crystal structure, where phosphate is bound to the active site Zn(II) ions. Fluoride uncompetitively inhibits sAP from pH 5.5 (K _i=3.72 mM) to 9.0 (43.6 mM), with a pK _a of ∼6.2 likely due to a coordinated water. The different inhibition natures and pK _a values indicate that the two inhibitors bind at different locations.

【 授权许可】

Unknown