The Pentose Phosphate Pathway

The Pentose Phosphate Pathway aims to explore the pentose phosphate cycle and the practical techniques applied in its investigation. The main focus of the book is the pentose phosphate cycle in animals as well as microorganisms, and does not discuss the one related to photosynthesis.
The book covers the formulation of the pathway, its types, and its alternative formulations; the preparation, processes, and analysis of the pathway; and the enzymes involved. Also covered in the book are the intermediates in intact cells and tissues; distribution of enzymes among different tissues and species; the operation, regulation, and overall control of the pathway; and the clinical, nutritional, and metabolic aspects of the pathway.
The text is recommended for biologists and biochemists who would like to understand further the pentose phosphate pathway and the processes related to it.

Contenu

Contents
Preface
List of Abbreviations
1 Introduction
Introduction
2 Formulation of the Pathway
Introduction
Experiments with Isotopes
The L-Type Pathway
Other Alternative Formulations of the Pathway
D-Erythrose 4-Phosphate as an Intermediate of the Pathway
The Transketolase-Transaldolase Coupled Reaction and the Existence of Enzyme Complexes
Conclusion
3 Preparation, Properties, and Analysis of the Intermediates of the Pathway
Introduction
General Analytical Methods
Preparation and General Chemistry
Individual Intermediates
4 Preparation, Properties, and Analysis of the Enzymes of the Pathway
Introduction
D-Ribose-5-Phosphate Ketol-Isomerase (EC 5.3.1.6)
D-Ribulose-5-Phosphate 3-Epimerase (EC 5.1.3.1)
Transaldolase (EC 2.2.1.2)
Transketolase (EC 2.2.1.1)
Other Enzymes
5 Intermediates in Intact Cells and Tissues
Introduction
Liver
Brain
Erythrocytes
Other Tissues
Ascites and HeLa Cells
Bacteria
Plants
Individual Intermediates
6 Distribution of the Enzymes among Different Tissues and Different Species
Introduction
General Surveys
Specific Tissues
Measurements on Other Species
Changes in Enzyme Levels during Development
Discussion
7 Operation and Regulation in Broken-Cell Preparations
Introduction
The Utilization of Different Substrates
8 Operation and Regulation in Intact Cells and Tissues
Introduction
Factors Stimulating the Oxidative Branch of the Pathway
The Effects of Changes in Physiological Factors on the Pathway
9 Overall Control of the Pathway
Introduction
Approach I: Rate-Limiting Enzymes
Approach II: Mass Action Ratios
Approach III: Cross-Over Plots
Approach IV: Enzymes under Hormonal and Allosteric Control
Approach V: Enzymes That Change in Response to Changes in the Environment
Control of the Oxidative Branch of the Pathway by an Activating Factor
Mathematical Models
Conclusion
10 Clinical and Nutritional Aspects
The Assay of Blood Transketolase
Normal Values for Blood Transketolase
The "TPP Effect"
Measurements of Other Enzymes
Clinical Studies of Various Pathological and Physiological States
Studies of Transketolase and Thiamine Deficiency in Other Species
The Mechanism of Activation of Transketolase by Thiamine
11 Glutathione Metabolism and the Pentose Phosphate Pathway
Text
12 Use of Radioisotopes in Elucidating the Nature of and Quantitating the Pentose Pathway
Introduction
The Nature of the Pathway
Quantitation
Conclusion
References
Index