/sup 35/Cl nuclear magnetic resonance studies of anion-binding sites in proteins: lactate dehydrogenase

Journal Article · Wed Jan 01 04:00:00 EST 1975 · Arch. Biochem. Biophys.; (United States)

DOI:https://doi.org/10.1016/0003-9861(75)90312-4· OSTI ID:7358701

Ward, R L

/sup 35/Cl nmr relaxation rate measurements have been used to study anion-binding sites in pig heart lactate dehydrogenase. These studies reveal two types of sites, one is intimately associated with the active site, the other is not. The nonactive site has been ascribed to a subunit site in analogy with crystallographic results from the dogfish M/sub 4/ enzyme. The binding of either the reduced or the oxidized form of NAD results in an increase in the /sup 35/Cl nmr relaxation rate by a factor of 1.8-2. The enhanced nmr relaxation rate of the binary lactate dehydrogenase--NAD complex is reduced on binding of the substrate inhibitor molecules oxamate or oxalate to a value less than that exhibited by lactate dehydrogenase alone. The enhancement of the nmr relaxation rate is attributed to a decrease in the dissociation constant of Cl/sup -/ for the enzyme. The K/sub D/ values for Cl/sup -/ binding to the active center site of lactate dehydrogenase are 0.85 M and for lactate dehydrogenase--NADH is 0.25 M. The ratio of these constants, 3.4, agrees well with the measured enhancement value 3.7. The effect of coenzyme analogs on the /sup 35/Cl nmr relaxation rate has been examined. 3-Acetylpyridine NAD produces an enhancement of 4.3, thionicotinamide NAD of 2.3, whereas 3-pyridinealdehyde, adenosinediphosphoribose, and adenosine diphosphate do not affect the nmr relaxation state of Cl/sup -/ bound to lactate dehydrogenase. (auth)

• Research Organization: Univ. of California, Livermore
• OSTI ID: 7358701
• Journal Information: Arch. Biochem. Biophys.; (United States), Journal Name: Arch. Biochem. Biophys.; (United States) Vol. 169; ISSN ABBIA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ANIONS
BIOCHEMISTRY
CHARGED PARTICLES
CHEMICAL BONDS
CHEMISTRY
CHLORINE 35
CHLORINE ISOTOPES
DEHYDROGENASES
ENZYMES
IONS
ISOTOPES
LACTATE DEHYDROGENASE
LIGHT NUCLEI
MAGNETIC RESONANCE
MOLECULAR STRUCTURE
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-EVEN NUCLEI
OXIDOREDUCTASES
RESONANCE
STABLE ISOTOPES