An investigation of the binding of protein proteinase inhibitors to trypsin by electrospray ionization mass spectrometry

FEBS Letters

Lowe, Gordon²  Green, Brian¹  Kraunsoe, James A.E.²  Aplin, Robin T.² 

[1] Micromass Ltd., Tudor Road, Altrincham WA14 5RZ, UK;Dyson Perrins Laboratory and Oxford Centre for Molecular Sciences, University of Oxford, South Parks Road, Oxford OX1 3QY, UK

关键词: Trypsin;    Bovine pancreatic trypsin inhibitor;    Soybean trypsin inhibitor;    Electrospray mass spectrometry;    Non-covalent binding;    ESI MS;    electrospray ionization mass spectrometry;    BPTI;    bovine pancreatic trypsin inhibitor;    SBTI;    soybean trypsin inhibitor type I-S;    K15V BPTI;    the site-directed mutant of BPTI in which Lys-15 is replaced by Val;    RcamBPTI;    a chemically modified BPTI in which the Cys-14–Cys-38 disulfide bond is reduced and the resultant free thiols are carboxyamidomethylated;    CV;    cone voltage;   

DOI  :  10.1016/0014-5793(96)01081-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The binding of BPTI and SBTI with trypsin has been investigated by ESI MS, using the mutant K15V-BPTI and the chemically modified RcamBPTI as controls. Although high cone voltages (+80 V) produce sharp spectra of BPTI, RcamBPTI, SBTI and trypsin alone, the complexes of BPTI, RcamBPTI and SBTI with trypsin undergo partial dissociation due to collisional activation. At lower cone voltages (+40 V) these non-covalent complexes are stable. The charge distribution on the trypsin and the inhibitors produced by gas phase dissociation of the complexes are markedly different from those of the components alone, indicating that ESI MS provides a novel probe for exploring the ionic interactions at the contact surface of proteins. Moreover, by determining the cone voltage at which the gas phase dissociation of complexes occurs it may be possible to use ESI MS to compare the binding energies of closely related complexes.

【 授权许可】

Unknown