Open AccessPurification and Characterization of Two Benzoyl-l-Tyrosine p-Nitroanilide Hydrolases from Etiolated Leaves of Zea mays L
Author(s) -
Mitsunobu Doi,
Yuzo Shioi
Publication year - 1987
Publication title -
plant physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.554
H-Index - 312
eISSN - 1532-2548
pISSN - 0032-0889
DOI - 10.1104/pp.84.3.770
Subject(s) - etiolation , enzyme , serine , molar concentration , tyrosine , proteases , zea mays , substrate (aquarium) , chemistry , protease , biochemistry , serine protease , michaelis–menten kinetics , stereochemistry , enzyme assay , biology , organic chemistry , agronomy , ecology
Two benzoyl-l-tyrosine p-nitroanilide hydrolases (BTPAases I and II) were purified from the etiolated leaves of Zea mays L. and characterized. BTPAase I was electrophoretically homogeneous and consisted of two identical subunits having a molecular weight of 53,000. The molecular weight of BTPAase II was 65,000. The Michaelis constants for substrate, BTPA, were 4 millimolar and 1.3 millimolar for BTPAases I and II, respectively. Based on the action of various inhibitors on both enzyme activities, these enzymes were classified as serine proteases. BTPAase I showed caseinolytic activity at neutral pH and the activity was strongly inhibited by the serine protease inhibitors.