Copper transport in the yeast Saccharomyces cerevisiae

Conference · Fri May 01 00:00:00 EDT 1987 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5849321

Martinez, L D; Connelly, J L

Biochemical processes involved in the movement of copper (Cu) into and out of the yeast Saccharomyces Cerevisiae have been investigated. Overall uptake of Cu was measured by disappearance of Cu from the reaction mixture by atomic absorption sensitive to 10/sup -10/M. The process of Cu influx is composed of a prerequisite binding and subsequent transport. The binding is non-energetic but is competitively inhibited by zinc(Zn). Transport is energetic as shown by an increased influx in the presence of added glucose. This process is prevented by 2,4-dinitrophenol(DNP). Cu influx is accompanied by an exchange for potassium(K) in a ratio of K:Cu=2:1. The process of Cu efflux involves a second type of binding site, probably of low affinity but large capacity. The presence of glucose causes the binding of extracellular Cu to these sites in a non-energy-dependent mechanism which prevents Cu efflux. Zn does not compete. DNP has no effect. The K:Cu ratio of 4:1 observed in the absence of glucose suggests a lowered net Cu uptake as a result of concomitant efflux activity. Finally, in the absence but not the presence of glucose, the pH of the extracellular solution increases. These observations are consistent with the idea that (a) yeast membrane has two Cu-binding sites, one of which participates in influx and one in efflux; (b) Cu exchanges with K during influx and with protons during efflux.

• Research Organization: Univ. of Southern Colorado, Pueblo
• OSTI ID: 5849321
• Report Number(s): CONF-870644-
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 46:6; Conference: 78. annual meeting of the American Society of Biological Chemists conference, Philadelphia, PA, USA, 7 Jun 1987
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
COPPER COMPOUNDS
MEMBRANE TRANSPORT
ABSORPTION SPECTROSCOPY
BIOCHEMICAL REACTION KINETICS
CATIONS
DINITROPHENOL
GLUCOSE
INHIBITION
PH VALUE
POTASSIUM COMPOUNDS
PROTONS
SACCHAROMYCES CEREVISIAE
UPTAKE
ZINC COMPOUNDS
ALDEHYDES
ALKALI METAL COMPOUNDS
AROMATICS
BARYONS
CARBOHYDRATES
CHARGED PARTICLES
ELEMENTARY PARTICLES
FERMIONS
FUNGI
HADRONS
HEXOSES
HYDROXY COMPOUNDS
IONS
KINETICS
MICROORGANISMS
MONOSACCHARIDES
NITRO COMPOUNDS
NUCLEONS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHENOLS
PLANTS
REACTION KINETICS
SACCHARIDES
SACCHAROMYCES
SPECTROSCOPY
TRANSITION ELEMENT COMPOUNDS
YEASTS
550700* - Microbiology
550200 - Biochemistry