Open AccessThe Hydrodynamic Properties and Kinetic Constants with Natural Substrates of the Esterase from Malus pumila Fruit
Author(s) -
GOODENOUGH Peter W.,
ENTWISTLE T. Gail
Publication year - 1982
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1982.tb06848.x
Subject(s) - chemistry , molecular mass , chromatography , esterase , isoelectric focusing , tetramer , isoelectric point , malus , ammonium , enzyme , organic chemistry , botany , biology
1 An esterase (EC 3.1.1.1) from Malus pumila fruit was purified to homogeneity using ammonium sulphate precipitation, absorption on hydroxyapatite, dye Matrex affinity chromatography, S.300 Sephacryl chromatography and wide‐range isoelectric focusing. 2 Kinetic constants of these preparations were established for a series of natural ester substrates. Greatest apparent affinity was for acetate esters containing seven or eight‐carbon skeletons and least for four‐carbon skeletons. 3 The purified protein gave a relative molecular mass of 195000. The enzyme appears to be a tetramer of similar sub‐units each with a relative molecular mass of 50000 4 Isoelectric focusing gave a single peak of activity with PI 9.33–9.66. 5 Specific activity increased considerably from small immature fruits to large fruit at the climacteric.