Localization and quantitation of chloroplast enzymes and light-harvesting components using immunocytochemical methods

Journal Article · Sat Sep 01 04:00:00 EDT 1990 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.94.1.334· OSTI ID:5915249

Mustardy, L; Cunningham, Jr, F X; Gantt, E ^[1]

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1. Univ. of Maryland, College Park (USA)

Seven chloroplast proteins were localized in Porphyridium cruentum (ATCC 50161) by immunolabeling with colloidal gold on electron microscope sections of log phase cells grown under red, green, and white light. Ribulose bisphosphate carboxylase labeling occurred almost exclusively in the pyrenoid. The major apoproteins of photosystem I (56-64 kD) occurred mostly over the stromal thylakoid region and also appeared over the thylakoids passing through the pyrenoid. Labeling for photosystem II core components (D2 and a 45 kD Chl-binding protein), for phycobilisomes (allophycocyanin, and a 91 kD L{sub CM} linker) and for ATP synthase ({beta} subunit) were predominantly present in the thylakoid region but not in the pyrenoid region of the chloroplast. Red light cells had increased labeling per thylakoid length for polypeptides of photosystem II and of phycobilisomes, while photosystem I density decreased, compared to white light cells. Conversely, green light cells had a decreased density of photosystem II and phycobilisome polypeptides, while photosystem I density changed little compared with white light cells. A comparison of the immunogold labeling results with data from spectroscopic methods and from rocket immunoelectrophoresis indicates that it can provide a quantitative measure of the relative amounts of protein components as well as their localization in specific organeller compartments.

• OSTI ID: 5915249
• Journal Information: Plant Physiology; (USA), Journal Name: Plant Physiology; (USA) Vol. 94:1; ISSN 0032-0889; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

551000* -- Physiological Systems
59 BASIC BIOLOGICAL SCIENCES
BIOLOGICAL EFFECTS
CARBON-CARBON LYASES
CARBOXY-LYASES
CARBOXYLASE
CELL CONSTITUENTS
CHLOROPLASTS
ELECTROMAGNETIC RADIATION
ENZYMES
LYASES
MEMBRANE PROTEINS
ORGANIC COMPOUNDS
PROTEINS
RADIATIONS
THYLAKOID MEMBRANE PROTEINS
VISIBLE RADIATION