Identification of Lys190 as the primary binding site for pyridoxal 5′‐phosphate in human serum albumin

FEBS Letters

Feldhoff, Richard C.¹  Fonda, Margaret L.¹  Bohney, James P.¹ 

[1] Department of Biochemistry, University of Louisville School of Medicine, Louisville, KY 40292, USA

关键词: Pyridoxal 5′-phosphate;    Vitamin B6;    Binding site;    Albumin (human);    PLP;    pyridoxal 5′-phosphate;    HSA;    human serum albumin;    BSA;    bovine serum albumin;    NEG;    nonenzymatic glycosylation;    PBS;    phosphate-buffered saline;   

DOI  :  10.1016/0014-5793(92)80073-P

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The covalent binding of pyridoxal 5′-phosphate (PLP) to human serum albumin (HSA) is important in the regulation of PLP metabolism. In plasma, PLP is bound to HSA at a single high-affinity and at two or more nonspecific sites. To characterize the primary PLP binding site, HSA was incubated with [³H]PLP, and the Schiff base linkage was reduced with potassium borohydride. Tryptic peptides were purified, and the major labeled peptide was sequenced. Amino acid analysis confirmed a homogeneous peptide Leu-Asp-Glu-Leu-Arg-Asp-Glu-Gly-Xaa-Ala-Ser-Ser-Ala-Lys which corresponds to residues 182–195 of HSA. The data indicate that Lys¹⁹⁰ is the primary PLP binding site. This Lys residue is distinct from other sites of covalent adduct formation; namely, the primary sites for nonenzymatic glycosylation (Lys³²⁵) and acetylation by aspirin (Lys¹⁹⁹).

【 授权许可】

Unknown