Purification and properties of an O-acetyl-transferase from Escherichia coli that can O-acetylate polysialic acid sequences
Certain strains of bacteria synthesize an outer polysialic acid (K1) capsule. Some strains of K1/sup +/ E.coli are also capable of adding O-acetyl-esters to the exocyclic hydroxyl groups of the sialic acid residues. Both the capsule and the O-acetyl modification have been correlated with differences in antigenicity and pathogenicity. The authors have developed an assay for an O-acetyl-transferase in E.coli that transfers O-(/sup 3/H)acetyl groups from (/sup 3/H)acetyl-Coenzyme A to colominic acid (fragments of the polysialic acid capsule). Using this assay, the enzyme was solubilized, and purified approx. 600-fold using a single affinity chromatography step with Procion Red-A Agarose. The enzyme also binds to Coenzyme A Sepharose, and can be eluted with high salt or Coenzyme A. The partially purified enzyme has a pH optimum of 7.0 - 7.5, is unaffected by divalent cations, is inhibited by high salt concentrations, is inhibited by Coenzyme A (50% inhibition at 100 ..mu..M), and shows an apparent Km for colominic acid of 3.7 mM (sialic acid concentration). This enzyme could be involved in the O-acetyl +/- form variation seen in some strains of K1/sup +/ E.coli.
- Research Organization:
- Univ. of California, San Diego
- OSTI ID:
- 6986055
- Report Number(s):
- CONF-8606151-; TRN: 86-039056
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
- Country of Publication:
- United States
- Language:
- English
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TRANSFERASES
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PURIFICATION
BIOASSAY
BIOCHEMICAL REACTION KINETICS
CHROMATOGRAPHY
COENZYMES
ESCHERICHIA COLI
TRACER TECHNIQUES
TRITIUM COMPOUNDS
BACTERIA
ENZYMES
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
MICROORGANISMS
REACTION KINETICS
SEPARATION PROCESSES
550201* - Biochemistry- Tracer Techniques