EurekaMag.com logo
+ Site Statistics
References:
53,214,146
Abstracts:
29,074,682
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Proton nmr carbon 13 nmr and phosphorus 31 nmr studies of the di hydro folate reductase nadp folate complex characterization of 3 coexisting conformational states



Proton nmr carbon 13 nmr and phosphorus 31 nmr studies of the di hydro folate reductase nadp folate complex characterization of 3 coexisting conformational states



Biochemistry 21(23): 5831-5838



The Lactobacillus casei dihydrofolate reductase-folate-NADP+ complex is shown by 1H and 13C NMR to exist in 3 interconverting conformational states, I, IIa and IIb. The proportions of the 3 states, as estimated from the intensities of the 3 separate 13C resonances observed in the complex containing [3-carboxamido-13C]NADP+, are pH dependent. State I predominates at low pH, and states IIa and IIb predominate at high pH; the ratio IIa:IIb is pH independent. The pH dependence of the interconversion of states I and IIa + IIb can be explained by a model in which a group on the enzyme has a pK of < 5 in state IIa + IIb and > 7 in state I. 1H, 13C and 31P NMR were used to characterize the structural differences between the 3 states of the complex. As judged by the 1H and 13C chemical shifts of the bound coenzyme, states I and IIa are similar to one another, but quite different from state IIb. This difference appears to be a localized one, since only the nicotinamide 2 and 4 protons, nicotinamide 3-carboxamide 13C and pteridine 7 proton show differences in chemical shift between these states. These differences are large, up to 1.4 ppm for 1H and 2 ppm for 13C. The remaining coenzyme protons and the 3 31P nuclei are unaffected. Studies of the C2 proton resonances of the 7 histidine residues show that the ionizable group responsible for the interconversion of states I and IIa + IIb is not a histidine (although 2 histidines show slight differences in environment between states IIa and IIb); the possible identity of this ionizable group and the nature of the conformational differences between the states are discussed.

(PDF 0-2 workdays service: $29.90)

Accession: 006215698

Download citation: RISBibTeXText



Related references

Hydrogen-1, carbon-13, and phosphorus-31 nuclear magnetic resonance studies of the dihydrofolate reductase-nicotinamide adenine dinucleotide phosphate-folate complex: characterization of three coexisting conformational states. Biochemistry 21(23): 5831-5838, 1982

Proton nmr and phosphorus 31 nmr characterization of 2 conformations of the trimethoprim nadp di hydro folate reductase complex. Molecular Pharmacology 20(1): 145-153, 1981

Studies on the regulation of 1 carbon metabolism the effects of folate concentration in the growth medium on the activity of 3 folate dependent enzymes in lactobacillus casei enz 10 formyl tetra hydro folate synthetase enz di hydro folate reductase enz 5 10 methylene tetra hydro folate dehydrogenase. Journal of Biological Chemistry 244(8): 1988-1993, 1969

Carbon 13 nmr evidence for 3 slowly inter converting conformations of the di hydro folate reductase nadp folate complex. Biochemical & Biophysical Research Communications 101(4): 1139-1144, 1981

Stereochemistry of di hydro folate reduction to tetra hydro folate direct hydrogen transfer to 6 carbon by escherichia coli mb 1428 di hydro folate reductase. Federation Proceedings 33(5 PART 2): 1382, 1974

Activity of the new anti folate n 10 propargyl 5 8 dideaza folate and its poly glutamates against human di hydro folate reductase human thymidylate synthetase and kb cells containing different levels of di hydro folate reductase. Federation Proceedings: Abstract 3890, 1984

Multinuclear NMR characterization of two coexisting conformational states of the Lactobacillus casei dihydrofolate reductase-trimethoprim-NADP+ complex. Biochemistry 23(20): 4733-4742, 1984

Multinuclear nmr characterization of 2 coexisting conformational states of the lactobacillus casei dihydrofolate reductase trimethoprim nadp complex. Biochemistry 23(20): 4733-4742, 1984

Di hydro folate reductase from escherichia coli mb 1428 effect of binding of folate di hydro folate and methotrexate upon uv absorbance. Federation Proceedings 32(3 PART 1): 592, 1973

Anti folate resistant chinese hamster cells messenger rna directed over production of multiple di hydro folate reductases from a series of independently derived sublines containing amplified di hydro folate reductase genes. Journal of Biological Chemistry 257(21): 12939-12949, 1982

Interaction of carbon 13 enriched folate with di hydro folate reductase studied by carbon magnetic resonance spectroscopy. Biochemical & Biophysical Research Communications 68(2): 471-475, 1976

Effect of 11 oxa homo folate and its reduced derivatives on human di hydro folate reductase ec 1513 and on human cells having different amounts of di hydro folate reductase. 1982

Di hydro folate reductase catalyzes 2 stereospecific reductions during conversion of folate to tetra hydro folate. Federation Proceedings: Abstract 2069, 1980

Methylene tetra hydro folate reductase steady state and rapid reaction studies on the nadph methylene tetra hydro folate nadph menadione and methyl tetra hydro folate menadione oxido reductase activities of the enzyme. Journal of Biological Chemistry 258(19): 11510-11514, 1983

In vitro studies of 5 10 methylene tetra hydro folate reductase ec 1.1.1.171 inhibition by folate derivatives folate antagonists and mono amine derivatives. Journal of Neurochemistry 38(3): 638-642, 1982