sup 1 H and sup 31 P nuclear magnetic resonance and kinetic studies of the active site structure of chloroplast CF sub 1 ATP synthase

Journal Article · Tue Jul 03 04:00:00 EDT 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00478a012· OSTI ID:6290743

Devlin, C C; Grisham, C M ^[1]

---

1. Univ. of Virginia, Charlottesville (USA)

The interaction of nucleotides and nucleotide analogues and their complexes with Mn{sup 2+} bound to both the latent and dithiothreitol-activated CF{sub 1} ATP synthase has been examined by means of steady-state kinetics, water proton relaxation rate (PRR) measurements, and {sup 1}H and {sup 31}P nuclear relaxation measurements. Titration of both the latent and activated Mn{sup 2+}-CF{sub 1} complexes with ATP, ADP, P{sub i}, Co(NH{sub 3}){sub 4}ATP, Co(NH{sub 3}){sub 4}ADP, and Co(NH{sub 3}){sub 4}AMPPCP leads to increases in the water relaxation enhancement, consistent with enhanced metal binding and a high ternary complex enhancement. Steady-state kinetic studies are consistent with competitive inhibition of CF{sub 1} by Co(NH{sub 3}){sub 4}AMPPCP with respect to CaATP. {sup 1}H and {sup 31}P nuclear relaxation measurements in solutions of CF{sub 1} and Co(NH{sub 3}){sub 4}AMPPCP were used to determine the conformation of the bound substrate analogue and the arrangement with respect to this structure of high- and low-affinity sites for Mn{sup 2+}. The bound nucleotide analogue adopts a bent conformation, with the low-affinity sites for Mn{sup 2+}. The bound nucleotide analogue adopts a bent conformation, with the low-affinity Mn{sup 2+} site situated between the adenine and triphosphate moieties and the high-affinity metal site located on the far side of the triphosphate chain. The low-affinity metal forms a distorted inner-sphere complex with the {beta}-P and {gamma}-P of the substrate. The distances from Mn{sup 2+} to the triphosphate chain are too large for first coordination sphere complexes but are appropriate for second-sphere complexes involving, for example, intervening hydrogen-bonded water molecules or residues from the protein.

• OSTI ID: 6290743
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 29:26; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ACID ANHYDRASES
ALGORITHMS
ATP-ASE
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CATIONS
CELL CONSTITUENTS
CHARGED PARTICLES
CHLOROPHYLL-BINDING PROTEINS
CHLOROPLASTS
DAYS LIVING RADIOISOTOPES
ELEMENTARY PARTICLES
ENZYME ACTIVITY
ENZYMES
FERMIONS
HADRONS
HYDROLASES
IONS
ISOTOPES
KINETICS
LIGHT NUCLEI
MAGNETIC RESONANCE
MANGANESE COMPOUNDS
MATHEMATICAL LOGIC
MOLECULAR STRUCTURE
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUCLEONS
NUCLEOTIDES
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHOSPHOHYDROLASES
PHOSPHORUS 31
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOTOSYNTHETIC REACTION CENTERS
PROTEINS
PROTONS
RADIOISOTOPES
REACTION KINETICS
RESONANCE
STABLE ISOTOPES
SUBSTRATES
TRANSITION ELEMENT COMPOUNDS