Biochemical Characterization of the SPATE Members EspPα and EspI

Toxins

André Weiss¹  David Kortemeier¹ 

[1] id="af1-toxins-06-02719">Institute of Food Chemistry, Corrensstraße 45, 48149 Münster, Germa

关键词: EspPα;    EspI;    SPATE;    virulence factor;    EHEC;    STEC;    biochemical characterisation;    substrate specificity;   

DOI  :  10.3390/toxins6092719

来源: mdpi

【 摘 要 】

The activity of serine proteases is influenced by their substrate specificity as well as by the physicochemical conditions. Here, we present the characterization of key biochemical features of the two SPATE members EspPα and EspI from Shiga-toxin producing Escherichia coli (STEC) and enterohemorrhagic E. coli (EHEC). Both proteases show high activity at conditions mimicking the human blood stream. Optimal activities were observed at slightly alkaline pH and low millimolar concentrations of the divalent cations Ca²⁺ and Mg²⁺ at physiological temperatures indicating a function in the human host. Furthermore, we provide the first cleavage profile for EspI demonstrating pronounced specificity of this protease.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.