Journal
INTERNATIONAL DAIRY JOURNAL
Volume 13, Issue 7, Pages 497-507Publisher
ELSEVIER SCI LTD
DOI: 10.1016/S0958-6946(03)00057-8
Keywords
Lactobacillus helveticus; X-prolyl dipeptidyl aminopeptidase; purification
Categories
Ask authors/readers for more resources
A X-prolyl dipeptidyl aminopeptidase (EC 3.4.14.5, XPDAP) from Lactobacillus helveticus ITG LH1, a strain used for Swiss-type cheese, was purified by ion exchange and affinity chromatographies. The enzyme appeared to be a 140 kDa monomer. Optimal activity occurred at pH 7 and 40 C, but it was rapidly inactivated above 50 C. The enzyme was activated by NaCl and KCl up to 50-200 mM but its activity levelled off at higher salt concentrations. Its complete inhibition was caused by 0.1 mM HgCl2 1 mM SnCl2 and 2.5 mm CuCl2. It was inactivated by reagents specific for serine proteases, such as phenylmethylsulfonyl fluoride and sulfhydryl group-blocking reagents. The enzyme hydrolysed p-nitroanilide-substituted X-Pro and X-Ala dipeptides, as well as beta-casomorphin 1-4. (C) 2003 Elsevier Science Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available