Copper transport across pea thylakoid membranes.
The initial rate of Cu2+ movement across the thylakoid membrane of pea (Pisum sativum) chloroplasts was directly measured by stopped-flow spectrofluorometry using membranes loaded with the Cu(2+)-sensitive fluorophore Phen Green SK. Cu2+ transport was rapid, reaching completion within 0.5 s. The initial rate of uptake was dependent upon Cu2+ concentration and saturated at about 0.6 microm total Cu2+. Cu2+ uptake was maximal at a thylakoid lumen pH of 7.0. Cu2+ transport was inhibited by Zn2+ but was largely unaffected by Mn2+ and Cu+. Zn2+ inhibited Cu2+ transport to a maximum of 60%, indicating that there may be more than one transporter for copper in pea thylakoid membranes.
Shingles
Richard
R
Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218-2685, USA. shingles@jhu.edu
Wimmers
Larry E
LE
McCarty
Richard E
RE
D001692:Biological Transport / Q000187:drug effects; D002412:Cations / Q000494:pharmacology; D002614:Chelating Agents / Q000494:pharmacology; D003300:Copper / Q000378:metabolism* / Q000494:pharmacology; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D009930:Organic Chemicals; D018532:Pisum sativum / Q000187:drug effects / Q000502:physiology*; D020524:Thylakoids / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors; D015032:Zinc / Q000494:pharmacology
D002412:Cations; D002614:Chelating Agents; D005456:Fluorescent Dyes; D009930:Organic Chemicals; C431805:Phen Green SK; D008345:Manganese; D003300:Copper; D015032:Zinc