[Purification and characterization of ribosome-associated histone acetyltransferase from rabbit reticulocytes].
Histone acetyltransferases from the ribosomes of rabbit reticulocytes were purified more than 100 fold. The procedures of purification included the following: acetyltransferases were released from ribosomes by 0.5 mol/L KCl treatment, then isolated by sedimentation through buffered sucrose containing 0.5 mol/L KCl. They were partially purified from the high salt washing fraction by sequential chromatography on histone-sepharose 4B, DEAE-cellulose 52 and phosphocellulose P11 columns and by nondenaturing polyacrylamide gel electrophoresis. Three main active bands were observed on 7.5% polyacrylamide gels under non-denaturing conditions with molecular weights of about 120,000, 70,000 and 40,000 respectively. The optimal pH for acetyltransferase activity was 7.5-8.0, and 1 mmol/L MgCl2 and 25 mmol/L KCl were required for activity. 70% of the activity was inhibited by 100 mmol/L MgCl2. The Michealis constants derived from double-reciprocal plots of the acetyltransferases for histone and acetyl coenzyme A were 1.2 mumol/L and 18-20 mumol/L respectively.
Qui
C
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Institute of Basic Medical Sciences, Beijing.
D000123:Acetyltransferases / Q000302:isolation & purification* / Q000378:metabolism; D000818:Animals; D002846:Chromatography, Affinity; D002848:Chromatography, DEAE-Cellulose; D051548:Histone Acetyltransferases; D006863:Hydrogen-Ion Concentration; D011817:Rabbits; D012156:Reticulocytes / Q000201:enzymology*; D012270:Ribosomes / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins
D029701:Saccharomyces cerevisiae Proteins; D000123:Acetyltransferases; D051548:Histone Acetyltransferases