[127] Enzymatic preparation of DPNH and TPNH

Rafter, Gale W.; Colowick, Sidney P.

doi:10.1016/s0076-6879(57)03471-0

Cited by 84 publications

(39 citation statements)

References 6 publications

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“…N-Methyldihydronicotinamide was prepared from N-methylnicotinamide iodide according to Rafter and Colowick (15) and stored in 10 mM sodium bicarbonate buffer at pH 10.5 (16). The concentrations of N-methyldihydronicotinamide solutions were determined by use of the molar absorption coefficient ( m ) of 7000 M Ϫ1 ⅐cm Ϫ1 at 360 nm (15). Enzyme Assays.…”

Section: Methodsmentioning

confidence: 99%

Unexpected genetic and structural relationships of a long-forgotten flavoenzyme to NAD(P)H:quinone reductase (DT-diaphorase)

Zhao

Yang

Holtzclaw

et al. 1997

Proc. Natl. Acad. Sci. U.S.A.

119

103

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following correction should be noted. On page 2475, the second line of the left column that reads ". . . were reconstituted with aly͞aly BM cells after lethal irradiation" should read ". . . were reconstituted with aly͞ϩ BM cells after lethal irradiation."Immunology. In the article "Modifying the sequence of an immunoglobulin V-gene alters the resulting pattern of hypermutation," by Beatriz Goyenechea and César Milstein, which appeared in number 24, November 26, 1996, of Proc. Natl. Acad. Sci. USA (93, 13979-13984), the following revision should be noted: The formula at the bottom of the first column of page 13980 was misprinted. The correct formula is:FIG. 6. Three-dimensional structure of rQR1 in complex with FAD and NADP ϩ (12). The C-terminal 43 amino acids (232-274) are shown in red (Left), and have been truncated at the arrow (Right). Different colors of the backbone indicate the two different subunits. It can be seen that the truncated portion of QR2 is critical for binding of the pyrophosphate moiety of the NAD(P)H cofactor. Note that the contact regions between the enzyme and FAD are presumably preserved in QR2 (Right), consistent with the tight binding of FAD. The structural comparison between rQR1 and hQR2 is appropriate since the homology between rQR1 and hQR1 is very high (85% identity). CorrectionsProc. Natl. Acad. Sci. USA 94 (1997)

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Section: Methodsmentioning

confidence: 99%

Unexpected genetic and structural relationships of a long-forgotten flavoenzyme to NAD(P)H:quinone reductase (DT-diaphorase)

Zhao

Yang

Holtzclaw

et al. 1997

Proc. Natl. Acad. Sci. U.S.A.

119

103

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“…NAD' (0), NADH (R) and 3-acetyl-pyridine NAD' were obtained from Sigma Chemical Company. The NAD' was repurified by the method of Dalziel [la].3-Acetyl-pyridine NADH was made by the method of Rafter and Colowick [19]. The fluorometric method of Theorell and McKinley-McKee [3] was used for kinetic experiments, with the exception that a commercial stabilized power supply (Oltronix) , was used with the photomultiplier of the fluorometer.…”

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confidence: 99%

Kinetics and Dissociation Constants of Liver Alcohol Dehydrogenase with 3‐Acetyl Pyridine NAD⁺ and NADH

Shore

Theorell²

1967

European Journal of Biochemistry

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Binary complex dissociation constants and kinetic di values of liver alcohol dehydrogenase were determined for 3-acetyl pyridine NAD' and NADH. The reduced analog was bound 24 times less tightly than NADH to liver alcohol dehydrogenase whereas no significant difference was found between the binding of 3-acetyl pyridine NAD' and NAD' to liver alcohol dehydrogenate. The rates of interaction of substrates with binary complexes were one tenth as fast when the acetyl pyridine analogs were used. These results were interpreted with reference to the significance of thc pyridine ring amide group in binding, and the interaction of binary complexes with substrates.The reaction mechanism of horse liver alcohol dehydrogenase has been studied extensively by Theorell and Chance [l 1, Dalziel [2], and Theorell andIt is now generally agreed that, from a kinetic point of view, the sequence is ordered with the first step being binding of coenzyme and the last step dissociation of coenzyme. Several recent publications [4,5] indicate that the enzyme can bind substrate first but this reaction is not kinetically significant.The binding of pyridine nucleotide coenzymes to the LADH has also been thoroughly investigated [6,7], indicating that NADH is much more tightly bound than NAD+. It had previously been postulated [S] that the amino group and the nitrogen atom in position 9 of the adenine ring of NAD' and NADH formed a bidentate chelate with the Zn atom at the active center of LADH. Subsequent studies by Yonetani [9] and Yonetani and Theorell [lo] demonstrated that it was possible to create an o-phenanthroline-enzyme-ADPR complex, and that the NAD' competitive inhibitions by ADPR and o-phenanthroline are additive. It therefore now seems probable that the ADPR part of the NAD+ is not involved in the formation of a bidentate Zn chelate. The fact that o-phenanthroline is an inhibitor competitive with NAD+ and NADH [ i l l indicates that the pyridine ring must interact with Zn.The 3-acetyl-pyridine analog of NAD' was first prepared by Kaplan and Ciotti [i2]. Subsequent studies indicated that the activity of this analog Abbreviations used. E or LADH, horse liver alcohol dehydrogenase (EC 1.1.1.1.); 0 or NADf, oxidized nicotinaniide adenine dinucleotide; R or NADH, reduced nicotinamide adenine dinucleotide; 3-AP, 3-acetyl pyridinc. ____with LADH was much faster than with NAD' under standard assay conditions at high alcohol concentrations [13], and that the binding of the reduced analog to LADH is accompanied by spectral [I41 and fluorescence emission [I51 shifts.The purpose of this study is to investigate the kinetics and equilibria of the LADH reaction using 3-acetyl-pyridine analogs of NAD' and NADH as coenzymes. Since the sequences of the LADH reactions with ordinary NAD' and NADH are fairly well established, and the steady-state equations describing them are known, the significance of the amide group on the pyridine ring in binding of the coenzyme can be to some extent evaluated. METHODS LADH (F,) was prepared according to Dalziel[1...

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“…(20) At pH 11.8 the reaction between tyrosine and N3' proceeds at a rate of 3.6 x 109 M-1 * s-1 whereas at pH 6.5 the rate is decreased to 1 x 108 M-1 s-l (Rafter & Colowick, 1957 (Fig. 1).…”

Section: Methodsmentioning

confidence: 98%

Thiyl and phenoxyl free radicals and NADH Direct observation of one-electron oxidation

Forni¹,

Willson²

1986

Biochemical Journal

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Absolute rate constants for the reaction of NADH with thiyl free radicals derived from various sulphurcontaining compounds of biological significance were measured by using the technique of pulse radiolysis. These and related reactions with phenoxyl free radicals are believed to occur through one-electron-transfer processes. Further evidence comes from studies with deuterated NADH. The results support the possibility that, in biochemical systems, thiols may act as catalysts linking hydrogen-atom and electron-transfer reactions.

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[127] Enzymatic preparation of DPNH and TPNH

Cited by 84 publications

References 6 publications

Unexpected genetic and structural relationships of a long-forgotten flavoenzyme to NAD(P)H:quinone reductase (DT-diaphorase)

Unexpected genetic and structural relationships of a long-forgotten flavoenzyme to NAD(P)H:quinone reductase (DT-diaphorase)

Kinetics and Dissociation Constants of Liver Alcohol Dehydrogenase with 3‐Acetyl Pyridine NAD⁺ and NADH

Thiyl and phenoxyl free radicals and NADH Direct observation of one-electron oxidation

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[127] Enzymatic preparation of DPNH and TPNH

Cited by 84 publications

References 6 publications

Unexpected genetic and structural relationships of a long-forgotten flavoenzyme to NAD(P)H:quinone reductase (DT-diaphorase)

Unexpected genetic and structural relationships of a long-forgotten flavoenzyme to NAD(P)H:quinone reductase (DT-diaphorase)

Kinetics and Dissociation Constants of Liver Alcohol Dehydrogenase with 3‐Acetyl Pyridine NAD+ and NADH

Thiyl and phenoxyl free radicals and NADH Direct observation of one-electron oxidation

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Kinetics and Dissociation Constants of Liver Alcohol Dehydrogenase with 3‐Acetyl Pyridine NAD⁺ and NADH