Open AccessPurification and Characterization of Esterase 6A, a Trimeric Esterase of the House Mouse (Mus musculus)
Author(s) -
OEHM HansChristian,
LOOZE Stephen,
RONAI Adam,
DEIMLING Otto
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.tb07034.x
Subject(s) - esterase , isoelectric focusing , isoelectric point , chemistry , chromatography , polyacrylamide gel electrophoresis , trimer , gel electrophoresis , electrophoresis , size exclusion chromatography , protein subunit , sodium dodecyl sulfate , biochemistry , enzyme , dimer , organic chemistry , gene
Esterase 6A was isolated from mouse lung and purified 440‐fold by ion‐exchange chromatography, inverse ammonium sulphate gradient solubilization, gel filtration and isoelectric focusing. The resultant product was apparently homogenous by the criteria of polyacrylamide gel electrophoresis and immunodiffusion, and consisted of the electrophoretic form 6A 3 . A single species of subunit was present on sodium dodecyl sulphate gel electrophoresis. The molecular weight of the native protein was found to be about 178000 with a subunit molecular weight of about 60000. The equivalent weight obtained by active‐site titration with diethyl‐ p ‐nitrophenyl phosphate was approximately 178000 g/mol, indicating a functional asymmetry in the trimer. The enzyme was shown to have a high affinity for 4‐nitrophenyl hexanoate (Michaelis constant K m = 4.4 μmol/l) with a relatively low catalytic efficiency (catalytic constant k cat = 12 s −1 ). Esterase 6A was immunologically related to esterase 1 and esterase 9, with which it is genetically closely linked. Further properties of the three esterases were compared.