Characterization of the recombinant exopeptidases PepX and PepN from Lactobacillus helveticus ATCC 12046 important for food protein hydrolysis.

ABSTRACT: The proline-specific X-prolyl dipeptidyl aminopeptidase (PepX; EC 3.4.14.11) and the general aminopeptidase N (PepN; EC 3.4.11.2) from Lactobacillus helveticus ATCC 12046 were produced recombinantly in E. coli BL21(DE3) via bioreactor cultivation. The maximum enzymatic activity obtained for PepX was 800 µkat(H-Ala-Pro-pNA) L(-1), which is approx. 195-fold higher than values published previously. To the best of our knowledge, PepN was expressed in E. coli at high levels for the first time. The PepN activity reached 1,000 µkat(H-Ala-pNA) L(-1). After an automated chromatographic purification, both peptidases were biochemically and kinetically characterized in detail. Substrate inhibition of PepN and product inhibition of both PepX and PepN were discovered for the first time. An apo-enzyme of

SUBMITTER: Stressler T 

PROVIDER: S-EPMC3716637 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature