The high stability of cruzipain against pH‐induced inactivation is not dependent on its C‐terminal domain

FEBS Letters

Björk, Ingemar¹  Turk, Boris³  McKerrow, James H.⁴  Cazzulo, Juan José²  Turk, Vito³  Stoka, Veronika³ 

[1] Department of Veterinary Medical Chemistry, Swedish University of Agricultural Sciences, Biomedical Center, P.O. Box 575, S-751 23 Uppsala, Sweden;Instituto de Investigaciones Biotecnológicas, Universidad Nacional de General San Martı́n, Casilla de Correo 30, 1650 San Martı́n, Provincia de Buenos Aires, Argentina;Department of Biochemistry and Molecular Biology, J. Stefan Institute, Jamova 39, Sl-1000 Ljubljana, Slovenia;Department of Pathology, University of California, San Francisco, CA 94143-0446, USA

关键词: Cruzipain;    Lysosomal cysteine protease;    Cathepsin;    pH-stability;    Trypanosoma cruzi;    EDTA;    ethylenediamine tetraacetic acid;    HEPES;    N-(2-hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid);    k obs;    observed inactivation rate constant;    k inac;    true inactivation rate constant;    MCA;    4-methyl-7-coumarylamide;    Z-;    benzyloxycarbonyl;   

DOI  :  10.1016/S0014-5793(00)01221-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Unlike mammalian lysosomal cysteine proteases, the trypanosomal cysteine protease cruzipain contains a 130-amino acid residue C-terminal domain, in addition to the catalytic domain, and it is stable at neutral pH. The endogenous (with C-terminal domain) and recombinant (without C-terminal domain) cruzipains exhibit similar stabilities at both acid (k_inac=3.1×10⁻³ s⁻¹ and 4.4×10⁻³ s⁻¹ at pH 2.75 for endogenous and recombinant cruzipain, respectively) and alkaline pH (k_inac=3.0×10⁻³ s⁻¹ and 3.7×10⁻³ s⁻¹ at pH 9.15 for endogenous and recombinant cruzipain, respectively). The pH-induced inactivation, which is a highly pH dependent first order process, is irreversible and accompanied by significant changes of secondary and tertiary structure as revealed by circular dichroism measurements. The different stability of cruzipain as compared to related proteases, is therefore due mainly to the different number, nature and distribution of charged residues within the catalytic domain and not due to addition of the C-terminal domain.

【 授权许可】

Unknown