QUANTITATIVE ASPECTS OF PECTIC ACID HYDROLYSIS BY ENDO‐POLYGALACTURONASE FROM Rhizopus Arrhizus

摘要

ABSTRACTThe mechanism of hydrolysis of various pectic substrates by highly purified endo‐polygalacturonase fromRhizopus arrhizus(RAPG) was investigated. RAPG hydrolyzed pectic acids through a random attack mechanism. Under controlled conditions, after hydrolysis of the pectic acid (DP = 134) by RAPG for 48 hr at 30°C, the major end products were monogalacturonic acid (6.5), dimer (18.0), trimer (55.0), tetramer (6.6), pentamer (5.1), hexamer (3.0), and small amounts of other oligomers. RAPG reacted more quickly on pectic acids of intermediate molecular weight (DP = 24), and favored pectic acid rather than pectinic acid and pecti