Sequence‐specific recognition of peptide substrates by the low M r phosphotyrosine protein phosphatase isoforms

FEBS Letters

Chiti, Fabrizio¹  Stefani, Massimo¹  Rigacci, Stefania¹  Taddei, Niccolò¹  Bucciantini, Monica¹  Ramponi, Giampietro¹ 

[1] Department of Biochemical Sciences, University of Florence, Viale Morgagni 50, 50134 Florence, Italy

关键词: Low M r phosphotyrosine protein phosphatase isoform;    Low M r phosphotyrosine protein phosphatase;    substrate recognition;    Platelet-derived growth factor-derived peptide;    Tyrosine-phosphorylated peptide;    PTPase;    phosphotyrosine protein phosphatase;    PTK;    protein tyrosine kinase;    low M r PTPase;    low molecular weight phosphotyrosine protein phosphatase;    IF1;    low M r PTPase isoform 1;    IF2;    low M r PTPase isoform 2;    AcP1;    rat liver low M r PTPase isoform 1;    AcP2;    rat liver low M r PTPase isoform 2;    PDGF;    platelet-derived growth factor;    Fmoc;    fluoren-9-ylmethoxycarbonyl-;    RP;    reverse phase;    OPfp;    pentafluorophenyl ester;    HOBt;    hydroxybenzotriazole;    BOC;    t-butyloxycarbonyl-;    Trt;    trityl-;    DMF;    dimethylformamide;    TFA;    trifluoroacetic acid;    TBTU;    2-(1H-benzotriazol-1-yl)-1;    1;    3;    3-tetramethyl uronium tetrafluoroborate;    TMSBr;    trimethylbromosilane;    TIS;    triisopropylsilane;    FAB;    fast atom bombardment;    RP-HPLC;    reverse phase-high performance liquid chromatography;    PNPP;    p-nitrophenylphosphate;   

DOI  :  10.1016/S0014-5793(98)00009-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A number of phosphotyrosine-containing peptides derived from the PDGF receptor phosphorylation sites have been synthesised. The peptides were assayed as substrates of the two isoforms (IF1 and IF2) of the low M _r PTPase. The calculated k _cat, K _m, and k _cat/K _m values indicate that only one peptide is best hydrolysed by IF2 (but not IF1), whose catalytic efficiency averages those previously reported for most PTPases (except the Yersinia enzyme). This peptide is the only one containing a couple of no bulky hydrophobic residues at the phosphotyrosine N-side. The determination of the same catalytic parameters in the presence of analogues of the best hydrolysed peptide in which one or both hydrophobic residues were replaced by Asp or Lys residues confirmed the importance of the hydrophobic cluster at the phosphotyrosine N-side for optimal enzymatic hydrolysis. These findings are discussed in the light of the known IF2 X-ray structure.

【 授权许可】

Unknown