Subsite mapping of human salivary α‐amylase and the mutant Y151M

FEBS Letters

Remenyik, Judit²  Kandra, Lili³  Gyémánt, Gyöngyi³  Ragunath, Chandran¹  Ramasubbu, Narayanan¹ 

[1] Department of Oral Biology, University of Medicine and Dentistry of New Jersey, Newark, NJ 07103, USA;Research Group for Carbohydrates of the Hungarian Academy of Sciences, P.O. Box 55, 4010 Debrecen, Hungary;Department of Biochemistry, Faculty of Sciences, University of Debrecen, P.O. Box 55, 4010 Debrecen, Hungary

关键词: Human salivary α-amylase;    Y151M mutant;    Action pattern;    Subsite map;    Binding energy;    Maltooligosaccharide;    HSA;    human salivary α-amylase;    HPA;    human pancreatic α-amylase;    PPA;    porcine pancreatic α-amylase;    BCF;    bond cleavage frequency;    CNP;    2-chloro-4-nitrophenyl;    DP;    degree of polymerization;    HPLC;    high-performance liquid chromatography;   

DOI  :  10.1016/S0014-5793(03)00495-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

This study characterizes the substrate-binding sites of human salivary α-amylase (HSA) and its Y151M mutant. It describes the first subsite maps, namely, the number of subsites, the position of cleavage sites and apparent subsite energies. The product pattern and cleavage frequencies were determined by high-performance liquid chromatography, utilizing a homologous series of chromophore-substituted maltooligosaccharides of degree of polymerization 3–10 as model substrates. The binding region of HSA is composed of four glycone and three aglycone-binding sites, while that of Tyr151Met is composed of four glycone and two aglycone-binding sites. The subsite maps show that Y151M has strikingly decreased binding energy at subsite (+2), where the mutation has occurred (−2.6 kJ/mol), compared to the binding energy at subsite (+2) of HSA (−12.0 kJ/mol).

【 授权许可】

Unknown