Binding of mercury compounds to the chloroplasts in relation to the inhibition of the Hill reaction

Journal Article · Sat Sep 01 04:00:00 EDT 1973 · Pestic. Biochem. Physiol.; (United States)

DOI:https://doi.org/10.1016/0048-3575(73)90019-9· OSTI ID:6238844

Lee, S S; Wauchope, R D; Haque, R; Fang, S C

The binding behavior of mercuric chloride (HgCl/sub 2/), phenylmercuric acetate (PMA), and ethylmercuric chloride (EMC) to the spinach chloroplasts in relation to the inhibition of the Hill reaction was studied at pH 6.8 and 7.8 using /sup 203/Hg labeled compounds. The pH of the reaction medium did not influence the amount of mercury binding of the chloroplast at various mercurial concentrations, but it altered the inhibition curve of the Hill reaction. Between 0-1 x 10/sup -5/ M the binding of Hg/sup 2 +/ and EMC were similar and increased linearly with the concentration, while the binding of PMA was similar to the binding of Hg/sup 2 +/ only at a concentration below 4 x 10/sup -6/ M and was less when the concentration was above 4 x 10/sup -6/ M. However, the inhibition of the Hill reaction by these mercury compounds was quite different; at ph 7.8, the I/sub 50/ values for Hg/sup 2 +/, PMA, and EMC were 5 x 10/sup -6/, 2.5 x 10/sup -6/, and 2.5 x 10/sup -6/ M, respectively, while at pH 6.8, these values were 4 x 10/sup -6/, 4 x 10/sup -5/, and 2 x 10/sup -4/ M, respectively. The differential block of electron flow by the mercury compounds at pH 6.8 and 7.8 was further confirmed by electron spin resonance study.

• Research Organization: Oregon State Univ., Corvallis
• OSTI ID: 6238844
• Journal Information: Pestic. Biochem. Physiol.; (United States), Journal Name: Pestic. Biochem. Physiol.; (United States) Vol. 3:3; ISSN PCBPB
• Country of Publication: United States
• Language: English

Related Subjects

560303* -- Chemicals Metabolism & Toxicology-- Plants-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
CELL CONSTITUENTS
CHLOROPLASTS
COMPARATIVE EVALUATIONS
CULTURE MEDIA
DAYS LIVING RADIOISOTOPES
ECOLOGICAL CONCENTRATION
EVEN-ODD NUCLEI
FOOD
HEAVY NUCLEI
INHIBITION
ISOTOPES
KINETICS
LABELLED COMPOUNDS
MERCURY 203
MERCURY COMPOUNDS
MERCURY ISOTOPES
NUCLEI
PH VALUE
PLANTS
RADIOISOTOPES
REACTION KINETICS
SPINACH
VEGETABLES