Premium
A STUDY OF THE MOLECULAR SIZES AND STABILITY OF CHOLINE ACETY LTRANSFER ASE
Author(s) -
Banns Heather E.
Publication year - 1976
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1976.tb06479.x
Subject(s) - sucrose gradient , chemistry , centrifugation , sucrose , size exclusion chromatography , chromatography , molecular mass , homogeneous , enzyme , biochemistry , physics , thermodynamics
— Aggregation of the enzyme acetyl‐CoA: choline‐ O ‐acetyltransferase (ChAc, EC 2.3.1.6) which appears to be homogeneous has been observed. The molecular weight of the most abundant form of ChAc was estimated by gel filtration and sucrose gradient centrifugation to be in the range 58,000‐62,000. The most frequently encountered aggregates were much larger and eluted in the void volume from Sephadcx® G‐100 and G‐150 indicating molecular weights in excess of 400,000. In fact, they were subsequently found to be 1.2 × 10 6 and 1.9 × 10 6 by sucrose gradient centrifugation. The percentage of activity associated with high molecular weight ChAc increased with purification, but these aggregates disappeared after storage for 2‐3 weeks at −20°C. The loss occurred independently of any fall in enzymic activity in the preparations examined.