Fluorinated substrate analogs as stereochemical probes of enzymic reaction mechanisms

Biochemistry ◽  
1978 ◽  
Vol 17 (25) ◽  
pp. 5567-5575 ◽  
Author(s):  
Jorge A. Goldstein ◽  
Yak-Fa Cheung ◽  
Michael A. Marletta ◽  
Christopher Walsh
Keyword(s):  
Reaction Mechanisms ◽  
Substrate Analogs ◽  
Enzymic Reaction

A SIMPLIFIED APPROACH TO THE USE OF DETERMINANTS IN THE CALCULATION OF THE RATE EQUATION FOR A COMPLEX ENZYME SYSTEM

1967 ◽  
Vol 45 (12) ◽  
pp. 2015-2039 ◽  
Author(s):  
R. O. Hurst
Keyword(s):  
Reaction Mechanism ◽  
Rate Equation ◽  
Rate Constants ◽  
Reaction Mechanisms ◽  
Enzyme System ◽  
Inhibition Mechanism ◽  
Simplified Approach ◽  
Enzymic Reaction ◽  
Dead End ◽  
Search For Information

A standardized method of treating the analysis of enzymic reaction mechanisms by means of determinant expressions is given. The fully expanded polynomial expressions for systems of order three, four, and five are presented and their use described. Application of the method to the analysis of the effect of dead-end inhibitors on enzymic reactions is discussed and the inhibitor constants are evaluated in terms of the rate constants involved in the inhibition mechanism. Examples are given to demonstrate the contribution that inhibitor studies may make in the search for information concerning the nature of the enzymic reaction mechanism, in the calculation of the rate constants, and in the estimation of the proportion of the enzyme distributed between the different enzyme forms involved in the reaction.

Mass spectral and 13C N.M.R. analyses of aminoglycoside aminocyclitols modified by enzyme-catalysed reactions

1981 ◽  
Vol 34 (3) ◽  
pp. 547 ◽  
Author(s):  
RG Coombe ◽  
AM George
Keyword(s):  
Mass Spectrometry ◽  
Reaction Mechanisms ◽  
Analytical Methods ◽  
Mass Spectral ◽  
Enzymic Reaction

Chemical and physical analytical methods, including mass spectrometry and 13C n.m.r., have been applied to the evaluation of the structures of the inactivated products of enzyme-mediated transferase reactions. Evidence is presented for the assignment of structures for the products of three enzymic reaction mechanisms: O-adenylylation, O-phosphorylation and N-acetylation.

Changing Enzymic Reaction Mechanisms by Mutagenesis: Conversion of a Retaining Glucosidase to an Inverting Enzyme

1994 ◽  
Vol 116 (25) ◽  
pp. 11594-11595 ◽  
Author(s):  
Qingping Wang ◽  
R. W. Graham ◽  
D. Trimbur ◽  
R. A. J. Warren ◽  
S. G. Withers
Keyword(s):  
Reaction Mechanisms ◽  
Enzymic Reaction

Analyzing reactions of single mechanoenzyme molecules by light microscopy

1992 ◽  
Vol 50 (1) ◽  
pp. 426-427
Author(s):  
Jeff Gelles
Keyword(s):  
Image Processing ◽  
Reaction Mechanisms ◽  
Transient State ◽  
Nanometer Scale ◽  
Reaction Intermediates ◽  
Enzyme Molecule ◽  
Directed Movement ◽  
Enzyme Molecules ◽  
Individual Enzyme ◽  
Single Reaction

Mechanoenzymes are enzymes which use a chemical reaction to power directed movement along biological polymer. Such enzymes include the cytoskeletal motors (e.g., myosins, dyneins, and kinesins) as well as nucleic acid polymerases and helicases. A single catalytic turnover of a mechanoenzyme moves the enzyme molecule along the polymer a distance on the order of 10−9 m We have developed light microscope and digital image processing methods to detect and measure nanometer-scale motions driven by single mechanoenzyme molecules. These techniques enable one to monitor the occurrence of single reaction steps and to measure the lifetimes of reaction intermediates in individual enzyme molecules. This information can be used to elucidate reaction mechanisms and determine microscopic rate constants. Such an approach circumvents difficulties encountered in the use of traditional transient-state kinetics techniques to examine mechanoenzyme reaction mechanisms.

X-Ray Microanalysis of Nickel and Cobalt Intensified Peroxidase- Antiperoxidase For Verification of Reaction Sites

1985 ◽  
Vol 43 ◽  
pp. 468-469
Author(s):  
A. Angel ◽  
K. Miller ◽  
V. Seybold ◽  
R. Kriebel
Keyword(s):  
Reaction Mechanisms ◽  
Visual Discrimination ◽  
Osmium Tetroxide ◽  
Ultrastructural Level ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
X Ray ◽  
Insoluble Polymer ◽  
Cytochemical Reaction

Localization of specific substances at the ultrastructural level is dependent on the introduction of chemicals which will complex and impart an electron density at specific reaction sites. Peroxidase-antiperoxidase(PAP) methods have been successfully applied at the electron microscopic level. The PAP complex is localized by addition of its substrate, hydrogen peroxide and an electron donor, usually diaminobenzidine(DAB). On oxidation, DAB forms an insoluble polymer which is able to chelate with osmium tetroxide becoming electron dense. Since verification of reactivity is visual, discrimination of reaction product from osmiophillic structures may be difficult. Recently, x-ray microanalysis has been applied to examine cytochemical reaction precipitates, their distribution in tissues, and to study cytochemical reaction mechanisms. For example, immunoreactive sites labelled with gold have been ascertained by means of x-ray microanalysis.

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