Open AccessThe pH6 Acetolactate‐Forming Enzyme from Aerobacter aerogenes Subunit Structure
Author(s) -
Huseby NilsErik,
Christensen Terje B.,
Olsen Bjørn Reino,
Størmer Fredrik C.
Publication year - 1971
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1971.tb01381.x
Subject(s) - dimer , protein subunit , sedimentation equilibrium , chemistry , guanidine , enzyme , gel electrophoresis , urea , electrophoresis , protein quaternary structure , molecular mass , ultracentrifuge , sedimentation coefficient , enterobacter aerogenes , polyacrylamide gel electrophoresis , aerobacter aerogenes , chromatography , crystallography , biochemistry , organic chemistry , escherichia coli , gene
The native and subunit molecular weights of the pH6 acetolactate‐forming enzyme from Aerobacter aerogenes have been investigated by sedimentation equilibrium analysis and gel electrophoresis. The values obtained are 220 000 for the native enzyme and 58 000 for its subunits. The native enzyme is dissociated into four equal‐sized subunits by exposure to guanidine hydrochloride, urea, or sodium dodecylsulfate. Electron micrographs of enzyme molecules, negatively stained, show that they appear as spherical particles with a diameter of about 6 nm forming dimeric structures of two particles close together. The molecular weight as calculated from the diameter of the particles, are consistent with the values obtained by sedimentation equilibrium and gel electrophoresis. The native enzyme molecule is visualized as a morphological dimer with each particle containing two polypeptide chains of similar size.