Physical and chemical characterization of a horse serum carboxylesterase.
The serine carboxylesterase from horse serum was characterized by amino acid composition, peptide mapping, molecular and subunit weights, and sequencing of the amino acids around the essential serine residue at the active site. A protocol was developed for using reversed-phase high-performance liquid chromatography as the final step to obtain homogeneous preparations of horse serum carboxylesterase. Amounts sufficient for determining the amino acid composition and for peptide maps were obtained from a partially purified starting material which contained approximately 55% carboxylesterase. The amino acid composition, like the subunit weight (70,800 +/- 1400), was similar to the corresponding values reported for other serine carboxylesterases. However, the amino acid sequence of the tryptic digest fragment containing the essential nucleophilic seryl residue differed significantly from the corresponding sequences of other mammalian serine carboxylesterases.
Torres
J L
JL
Biochemistry Department, North Carolina State University, Raleigh 27695.
Rush
R S
RS
Main
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AR
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000097:blood; D000818:Animals; D001665:Binding Sites; D043182:Carboxylesterase; D002265:Carboxylic Ester Hydrolases / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D004586:Electrophoresis / Q000379:methods; D004789:Enzyme Activation; D006736:Horses; D006868:Hydrolysis; D008099:Liver / Q000201:enzymology; D008970:Molecular Weight; D010446:Peptide Fragments / Q000097:blood; D010449:Peptide Mapping; D011817:Rabbits; D013379:Substrate Specificity; D014357:Trypsin
D000596:Amino Acids; D010446:Peptide Fragments; D002265:Carboxylic Ester Hydrolases; D043182:Carboxylesterase; D014357:Trypsin