Specificity characterization of the α-mating factor hormone by Kex2 protease.

Autor: Manfredi MA; Centro Interdisciplinar de Investigação Bioquímica, Universidade de Mogi das Cruzes - UMC, Mogi das Cruzes, SP, Brazil., Antunes AA; Centro Interdisciplinar de Investigação Bioquímica, Universidade de Mogi das Cruzes - UMC, Mogi das Cruzes, SP, Brazil., Jesus LO; Centro Interdisciplinar de Investigação Bioquímica, Universidade de Mogi das Cruzes - UMC, Mogi das Cruzes, SP, Brazil., Juliano MA; Departamento de Biofísica, Escola Paulista de Medicina, Universidade Federal de São Paulo, Rua Três de Maio, 100, São Paulo, SP, 04044-020, Brazil., Juliano L; Departamento de Biofísica, Escola Paulista de Medicina, Universidade Federal de São Paulo, Rua Três de Maio, 100, São Paulo, SP, 04044-020, Brazil., Judice WA; Centro Interdisciplinar de Investigação Bioquímica, Universidade de Mogi das Cruzes - UMC, Mogi das Cruzes, SP, Brazil. Electronic address: wagneras@umc.br.
Jazyk: angličtina
Zdroj: Biochimie [Biochimie] 2016 Dec; Vol. 131, pp. 149-158. Date of Electronic Publication: 2016 Oct 05.
DOI: 10.1016/j.biochi.2016.10.003
Abstrakt: Kex2 is a Ca 2+ -dependent serine protease from S. cerevisiae. Characterization of the substrate specificity of Kex2 is of particular interest because this protease serves as the prototype of a large family of eukaryotic subtilisin-related proprotein-processing proteases that cleave sites consisting of pairs or clusters of basic residues. Our goal was to study the prime region subsite S' of Kex2 because previous studies have only taken into account non-prime sites using AMC substrates but not the specificity of prime sites identified through structural modeling or predicted cleavage sites. Therefore, we used peptides derived from Abz-KR↓EADQ-EDDnp and Abz-YKR↓EADQ-EDDnp based on the pro-α-mating factor sequence. The specificity of Kex2 due to basic residues at P 1 ' is affected by the type of residue in the P 3 position. Some residues in P 1 ' with large or bulky side chains yielded poor substrate specificity. The k cat /K M values for peptides with P 2 ' substitutions containing Tyr in P 3 were higher than those obtained for the peptides without Tyr. In fact, P' and P modifications mainly promoted changes in k cat and K M , respectively. The pH profile of Kex2 was fit to a double-sigmoidal pH-titration curve. The specificity results suggest that Kex2 might be involved in the processing of the putative cleavage sites in a polypeptide involved in cell elongation, hyphal formation and the processing of a toxin, which result in host cell lysis. In summary, the specificity of Kex2 is dependent on the set of interactions with prime and non-prime subsites, resulting in synergism.
(Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.)
Databáze: MEDLINE
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