Localization of the steroid‐binding site of the human sex steroid‐binding protein of plasma (SBP or SHBG) by site‐directed mutagenesis

FEBS Letters

Sui, Li-ming¹  Namkung, Pearl C.¹  Cheung, Audrey W.C.¹  Petra, Philip H.¹ 

[1]Department of Obstetrics and Gynecology, University of Washington, Seattle, WA 98195, USA

关键词: Sex steroid-binding protein;    SBP;    Sex hormone binding globulin;    SHBG;    Mammalian expression;    Site-directed mutagenesis;   

DOI  :  10.1016/0014-5793(92)81309-A

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The amino-terminal region of the human sex steroid-binding protein of plasma (SBP or SHBG) containing K134 and M139 was found to represent part of the steroid-binding site. This was accomplished by constructing and expressing site-directed mutants having the following replacements: M139L, M139K, M139S, K134A, H235S, and Y57F. The results indicated that M139L and H235S were fully-active, K134A and Y57F were 50 and 67% active, M139K was 7% active, and M 139S was inactive. These results support affinity-labeling data indicating that both K134 and M139 are located in or near the site, and suggest that Y57 may play a role in steroid binding. The fully active H235S mutant reveals that H235 is not involved in the steroid-binding process.

【 授权许可】

Unknown