Formation of putative chloroplast cytochromes in isolated developing pea chloroplasts

Conference · Tue Apr 01 00:00:00 EST 1986 · Plant Physiol., Suppl.; (United States)

OSTI ID:5004645

Thaver, S S; Bhava, D; Castelfranco, P A

In addition to chlorophyll-protein complexes, other proteins were labeled when isolated developing pea chloroplasts were incubated with (/sup 14/C)-5-aminolevulinic acid (/sup 14/C)-ALA. The major labeled band (M/sub r/ = 43 kDa by LDS-PAGE) was labeled even in the presence of chloramphenicol. Heme-dependent peroxidase activity (as detected by the tetramethyl benzidine-H/sub 2/O/sub 2/ stain) was not visibly associated with this band. The radioactive band was stable to heat, 5% HCl in acetone, and was absent if the incubation with (/sup 14/C)-5-aminolevulinic acid was carried out in the presence of N-methyl protoporphyrin IX dimethyl ester (a specific inhibitor of ferrochelatase). Organic solvent extraction procedures for the enrichment of cytochrome f from chloroplast membranes also extracted this unknown labeled product. It was concluded that this labeled product was probably a c-type cytochrome. The effect of exogenous iron, iron chelators, gabaculine (an inhibitor of ALA synthesis) and other incubation conditions upon the in vitro formation of putative chloroplast cytochromes will be discussed.

• Research Organization: Univ. of California, Davis
• OSTI ID: 5004645
• Journal Information: Plant Physiol., Suppl.; (United States), Vol. 80:4; Conference: Annual meeting of the American Society of Plant Physiologists, Baton Rouge, LA, USA, 8-12 Jun 1986
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CYTOCHROMES
BIOSYNTHESIS
PLANT CELLS
CARBON 14 COMPOUNDS
CHLOROPHYLL
LABELLING
PISUM
BACTERIA
CARBOXYLIC ACIDS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
LABELLED COMPOUNDS
LEGUMINOSAE
MICROORGANISMS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHYTOCHROMES
PIGMENTS
PLANTS
PORPHYRINS
PROTEINS
RHIZOBIUM
SYNTHESIS
551001* - Physiological Systems- Tracer Techniques