Evidence for essential lysyl residues in ribulosebisphosphate carboxylase by use of the affinity label 3-bromo-1,4-dihydroxy-2-butanone 1,4-bisphosphate
A previous study from our laboratory suggested that 3-bromo-1,4-dihydroxy-2-butanone 1,4-bisphosphate is an affinity label for spinach ribulosebisphosphate carboxylase. To identify the essential residues that react with the reagent we have isolated and characterized the labeled peptides that are present in tryptic digests of inactivated enzyme but lacking in digests of the substrate-protected enzyme. Peptides representing two sites of modification have been obtained from the inactivated carboxylase. Both sites of reaction have been identified as lysyl residues based on the conversion of the derivatives to free lysine by oxidation with sodium metaperiodate. Sodium sulfate-gel electrophoretic experiments show that both essential lysyl residues are contained within the large subunit of ribulosebisphosphate carboxylase. In addition to lysyl residues, sulfhydryl groups of the carboxylase are also modified, but their modification seems to play little role in the inactivation process. The carboxylase modified in the presence of substrate contains sulfhydryl derivatives but is essentially lacking in lysyl derivatives. By comparing the profiles from ion exchange chromatography of labeled peptides in digests of inactivated and substrate-protected enzyme, we conclude that the same sulfhydryl groups are modified in the absence and presence of substrate. (auth)
- Research Organization:
- Oak Ridge National Lab., TN
- OSTI ID:
- 7352767
- Journal Information:
- J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 250:20; ISSN JBCHA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Identification of essential lysyl and cysteinyl residues in spinach ribulosebisphosphate carboxylase/oxygenase modified by the affinity label n-bromoacetylethanolamine phosphate
Sequences of two active-site peptides from spinach ribulosebisphosphate carboxylase/oxygenase
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
AFFINITY
BIOCHEMICAL REACTION KINETICS
CARBOHYDRATES
CARBOXYLASE
ENZYMES
FOOD
KETONES
KINETICS
LYASES
MONOSACCHARIDES
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PENTOSES
PEPTIDES
PHOSPHATES
PHOSPHORUS COMPOUNDS
PROTEINS
RADICALS
REACTION KINETICS
RIBULOSE
SACCHARIDES
SPINACH
SULFHYDRYL RADICALS
VEGETABLES