Binding of GM1‐ganglioside to a synthetic peptide derived from the lysosomal sphingolipid‐activator‐protein saposin B

FEBS Letters

Lamontagne, Sonia¹  Potier, Michel¹  Champagne, Marie-Josée¹ 

[1] Service de Génétique Médicale, Hôpital Sainte-Justine, et Département de Pédiatrie et de Biochimie, Université de Montréal, Montréal, Québec, H3T 1C5, Canada

关键词: Saposin B;    GM1-ganglioside;    Lysosomal disease;   

DOI  :  10.1016/0014-5793(94)00536-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Saposin B is a lysosomal sphingolipid-activator-protein which activates GM1-ganglioside hydrolysis by lysosomal β-galactosidase. To identify the structural elements of saposin B implicated in sphingolipid binding, we studied a synthetic peptide corresponding to a predicted α-helix, sapB-18, spanning residues 52 to 69 of saposin B. The circular dichroism spectrum of sapB-18 at pH 4.4 was consistent with a 44% α-helix content. As shown by intrinsic Tyr fluorescence studies of sapB-18, this peptide binds the GM 1 -ganglioside with a K _d of about 7μM. Thus, we suggest that a putative amphipathic α-helix between residues 52 and 69 of saposin B plays a major role in the recognition and binding of GM1-ganglioside by saposin B.

【 授权许可】

Unknown