Platinum tetrachloride: mutagenicity and methylation with methylcobalamin

Journal Article · Mon Jan 01 04:00:00 EST 1979 · J. Environ. Sci. Health, Part A; (United States)

DOI:https://doi.org/10.1080/10934527909374864· OSTI ID:5366858

Taylor, R T; Happe, J A; Hanna, M L; Wu, R

It was reported earlier that methylcobalamin (MeB-12) plus K/sub 2/PtCl/sub 6/ or Na/sub 2/PtCl/sub 6/ under acidic conditions yields a single square planar Pt/sup 2 +/ species, MePtCl/sub 3//sup 2 -/. A reaction between MeB-12 and PtCl, in H/sub 2/O has now been shown to occur. Complete demethylation requires two equivalents of PtCl/sub 4/ and MePtCl/sub 3//sup 2 -/ is the principal product. In addition, a second Me-Pt product has been detected and isolated. It has a Me/Pt ratio of 1.0, but it lacks the 260 nm absorption maximum of MePtCl/sub 3//sup 2 -/ and it has a lower electrophoretic mobility at pH 4.5. The proton NMR spectrum of this product shows a typical triplet pattern, but the chemical shift of the center band and the spin coupling constant change with pH. Its NMR parameters suggest that this species is MePt(H/sub 2/O)Cl/sub 2//sup 1 -/ (pKa ca. 4.5). A linear bridged intermediate is proposed to account for the methylation products obtained from MeB-12 and K/sub 2/PtCl/sub 6/ (or PtCl/sub 4/) and the catalytic role of K/sub 2/PtCl/sub 4/. As part of a systematic study of Pt-complex mutagenesis, we also report quantitative data on the cytotoxicity and mutagenicity of PtCl/sub 4/ in two closely related Chinese hamster ovary lines, CHO-S and CHO-AUXB1. In CHO-S cells PtCl/sub 4/ induces forward mutations to 8-azaguanine resistance/hypoxanthine-guanine phosphoribosyl transferase locus (8-AG/sup R//HGPRT locus), but not to ouabain resistance (OUA/sup R/). It also induces the reversion of CHO AUXB1, a triple auxotroph. The mutagenic effects of PtCl/sub 4/ in both CHO lines are dose dependent in the 5-30 ..mu..M concentration range.

• Research Organization: Univ. of California, Livermore
• OSTI ID: 5366858
• Journal Information: J. Environ. Sci. Health, Part A; (United States), Journal Name: J. Environ. Sci. Health, Part A; (United States) Vol. 14:2; ISSN JESED
• Country of Publication: United States
• Language: English

Related Subjects

550200 -- Biochemistry
550300 -- Cytology
560301* -- Chemicals Metabolism & Toxicology-- Cells-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOCHEMICAL REACTION KINETICS
BODY
CATALYTIC CONVERTERS
CELL CULTURES
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
DOSE-RESPONSE RELATIONSHIPS
EQUIPMENT
EXHAUST GASES
FEMALE GENITALS
GASEOUS WASTES
GONADS
HALIDES
HALOGEN COMPOUNDS
HAMSTERS
KINETICS
MAGNETIC RESONANCE
MAMMALS
METHYLATION
MUTAGENESIS
NUCLEAR MAGNETIC RESONANCE
ORGANS
OVARIES
PLATINUM CHLORIDES
PLATINUM COMPOUNDS
POLLUTION CONTROL EQUIPMENT
REACTION KINETICS
RESONANCE
RODENTS
STRUCTURAL CHEMICAL ANALYSIS
TOXICITY
TRANSITION ELEMENT COMPOUNDS
VERTEBRATES
VITAMIN B GROUP
VITAMIN B-12
VITAMINS
WASTES