A study of D52S hen lysozyme‐G1cNAc oligosaccharide complexes by NMR spectroscopy and electrospray mass spectrometry

FEBS Letters

Jeenes, David J.²  Lambert, Nigel²  Lowe, Gordon³  Dobson, Christopher M.¹  MacKenzie, Donald A.²  Archer, David B.²  Radford, Sheena E.¹  Aplin, Robin T.³  Lumb, Kevin J.¹ 

[1] Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, UK;Agricultural and Food Research Council Institute of Food Research, Norwich Laboratory, Colney Lane, Norwich, NR4 7UA, UK;Dyson Perrins Laboratory, University of Oxford, South Parks road, Oxford, OX1 3QY, UK

关键词: Hen lysozyme;    Active site mutant;    1H NMR;    Electrospray mass spectrometry;    D52S lysozyme;    the site-directed mutant of hen lysozyme in which Asp-52 is replaced by Ser;    GlcNAcn;    β(1→4)-linked N-acetyl glucosimine of order n;    MurNAc;    N-acetylmuramic acid;    ESMS;    electrospray mass spectrometry;    DQF COSY;    double quantum filtered correlated spectroscopy;    NOESY;    nuclear Overhauser enhancement spectroscopy;    NMR;    nuclear magnetic resonance spectroscopy;   

DOI  :  10.1016/0014-5793(92)80368-Q

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The production of a mutant hen lysozyme is described in which Asp-52, one of the catalytically important residues, is replaced by Ser. The mutant enzyme has very low catalytic activity but NMR studies show that its structure is closely similar to that of the wild-type protein. NMR experiments also show that well defined complexes are formed with GlcNAc₄ and GlcNAc₆ bound in the active Site of the mutant enzyme. Then complexes have been examined using electrospray mass spectrometry (ESMS). The most intense peaks arise from the uncomplexed protein indicating that dissociation takes place in the mass spectrometer under the conditions used here. Peaks from minor species corresponding to complexes between the protein and the oligosaccharides are, however, also observed. The possibility that the latter arise from novel covalent enzyme-saccharide complexes is discussed.

【 授权许可】

Unknown