Purification and characterization of ribulose-5-phosphate kinase from spinach

Journal Article · Fri Feb 14 23:00:00 EST 1986 · Arch. Biochem. Biophys.; (United States)

DOI:https://doi.org/10.1016/0003-9861(86)90185-2· OSTI ID:5734603

Porter, M A; Milanez, S; Stringer, C D; Hartman, F C

An efficient purification procedure utilizing affinity chromatography is described for spinach ribulose-5-phosphate kinase, a light-regulated chloroplastic enzyme. Gel filtration and polyacrylamide gel electrophoresis of the purified enzyme reveal a dimeric structure of 44,000 Mr subunits. Chemical crosslinking with dimethyl suberimidate confirms the presence of two subunits per molecule of native kinase, which are shown to be identical by partial NH2-terminal sequencing. Based on sulfhydryl titrations and on amino acid analyses, each subunit contains four to five cysteinyl residues. The observed slow loss of activity during spontaneous oxidation in air-saturated buffer correlates with the intramolecular oxidation of two sulfhydryl groups, presumably those involved in thioredoxin-mediated regulation.

• Research Organization: Oak Ridge National Lab., TN
• OSTI ID: 5734603
• Journal Information: Arch. Biochem. Biophys.; (United States), Journal Name: Arch. Biochem. Biophys.; (United States) Vol. 1; ISSN ABBIA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CHLOROPLASTS
CHROMATOGRAPHY
ENZYMES
FOOD
MOLECULAR STRUCTURE
MOLECULAR WEIGHT
ORGANIC ACIDS
ORGANIC COMPOUNDS
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
PLANTS
PURIFICATION
SEPARATION PROCESSES
SPINACH
TRANSFERASES
VEGETABLES