Heparan N‐sulfatase: cysteine 70 plays a role in the enzyme catalysis and processing

FEBS Letters

Di Natale, Paola¹  Daniele, Aurora¹ 

[1]Department of Biochemistry and Medical Biotechnologies, Medical School, University of Naples Federico II, Via Pansini 5, 80131 Naples, Italy

关键词: Heparan N-sulfatase;    Mucopolysaccharidosis IIIA;    Protein processing;    Immunoglobulin binding protein;    MPS-IIIA;    mucopolysaccharidosis type IIIA;    NS;    heparan N-sulfatase;    wt;    wild-type;    BiP;    immunoglobulin binding protein;    RER;    rough endoplasmic reticulum;   

DOI  :  10.1016/S0014-5793(01)02867-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Sulfatases are members of a highly conserved family of enzymes that catalyze the hydrolysis of sulfate ester bonds from a variety of substrates. The functional correlation reflects a high degree of amino acid sequence similarity along the entire length, in particular in the active site where the C(X)PSR consensus sequence is present. Cysteine undergoes an important co- or post-translation modification essential for the accomplishment of catalytic activity: conversion in formylglycine. In this work, the cysteine of heparan N-sulfatase (NS) was replaced either by a serine (C70S) or by a methionine (C70M) using site-directed mutagenesis. C70S and C70M mutant cDNAs were expressed and analyzed in COS cells; both mutations caused a loss of NS activity; however, while C70S showed a normal precursor form undergoing processing to a reduced mature form within the lysosomes, C70M was poorly synthesized and formed a complex with the molecular chaperone immunoglobulin binding protein.

【 授权许可】

Unknown