Bicarbonate is a recycling substrate for cyanase

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

OSTI ID:6074987

Johnson, W V; Anderson, P M

Cyanase catalyzes HCO/sub 3//sup -/-dependent decomposition of cyanate to NH/sub 4//sup +/ and HCO/sub 3//sup -/. Previous studies provided evidence that carbamate is an initial product and that the kinetic mechanism is rapid equilibrium random (HCO/sub 3//sup -/ serving as substrate as opposed to activator). Direct evidence for this mechanism was obtained in this study by (1) identifying the products formed from (/sup 14/C)HCO/sub 3//sup -/ or (/sup 14/C)OCN/sup -/, (2) identifying the products formed from (/sup 13/C)HCO/sub 3//sup -/ in the presence of (/sup 18/O)H/sub 2/O, and (3) determining whether CO/sub 2/ or HCO/sub 3//sup -/ serve as substrate and are formed as product. Carbon dioxide (not HCO/sub 3//sup -/) is produced in stoichiometric amounts from both HCO/sub 3//sup -/ and OCN/sup -/. Bicarbonate (not CO/sub 2/) is the substrate. Oxygen-18 from (/sup 18/O)H/sub 2/O is not incorporated into CO/sub 2/ formed from either HCO/sub 3//sup -/ or OCN/sup -/. These results indicate that decomposition of cyanate is not a hydrolysis reaction and that HCO/sub 3//sup -/ functions as a substrate.

• Research Organization: Univ. of Minnesota, Duluth
• OSTI ID: 6074987
• Report Number(s): CONF-870644-; TRN: 87-037117
• 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
ACID CARBONATES
BIOLOGICAL FUNCTIONS
LYASES
SUBSTRATES
CARBON 13
CARBON 14 COMPOUNDS
CARBON DIOXIDE
OXYGEN 18
STOICHIOMETRY
TRACER TECHNIQUES
WATER
CARBON COMPOUNDS
CARBON ISOTOPES
CARBON OXIDES
CHALCOGENIDES
ENZYMES
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FUNCTIONS
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
NUCLEI
OXIDES
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
STABLE ISOTOPES
550201* - Biochemistry- Tracer Techniques