Main description:

After the great achievements in the field of molecular foundations of genetics and protein synthesis, molecular biology undertook the successful deciphering of a number of other important biological problems. By this time ecology in its various branches was far enough advanced to tackle the problems arising at the level of molecular biology. The monograph of Professor Alexandrov, which takes as an example the adaptation of organisms to habitat temperatures, presents a vivid picture of this major ecological problem as viewed at the cellular and molecular levels. As main theme of the book the author advances a hypothesis on a correlation between the level of conformational flexibility of protein molecules and the temperature ecology of a species, as a result of which the protein molecules are maintained in a semilabile state. This principle may also be applied to other factors of the environment which affect the level of flexibility of protein macro molecules. The principle of semistability is shown to be applicable also to the nucleic and fatty acids.

Contents:

1. Modificational Changes of the Primary Thermoresistance of Cells.- 1.1 The Primary Thermoresistance of Cells.- 1.1.1 The Primary and General Thermostability of Cells.- 1.1.2 Biochemical Aspects of Primary Thermoresistance.- 1.1.3 Methods for Evaluation of Primary Thermostability of Cells.- 1.2 The Level of Primary Thermostability of Cells and Habitat Temperature.- 1.2.1 Effects of Temperature Variations Within the Tolerant Zone on Primary Thermostability of Cells (the Temperature Adjustment).- 1.2.1.1 Protozoa.- 1.2.1.2 Algae.- 1.2.1.3 Animal Tissue Cells.- 1.2.1.4 Plant Tissue Cells.- Summary.- 1.2.2 Effects of Habitat Temperature Variations Outside the Tolerant Zone Upon the Primary Thermostability of Cells (Temperature Hardenings).- 1.2.2.1 Heat Hardening of Plant Cells.- 1.2.2.2 Heat Hardening of Animal Cells.- Summary.- 1.2.2.3 Modification of Thermostability of Plant Cells by Cold Hardening.- 1.3 Changes in the Cellular Primary Thermostability Produced by Non-Temperature Factors.- 1.3.1 Variations in Cellular Thermostability During Growth and Development of Plants.- 1.3.2 Changes of Thermostability of Animal Cells in Ontogenesis.- 1.3.3 Changes in Thermostability of Plant Cells Caused by Water Deficiency.- 1.3.4 Effects of Salinity on Thermoresistance of Cells.- 1.3.5 Effects of Wound Injury on Thermostability of Plant Cells.- Summary.- 2. Genotypic Changes of the Primary Thermoresistance of Cells.- 2.1 Animals.- 2.2 Plants.- 2.3 Microorganisms.- Summary.- 3. Variations in Thermostability of Protoplasmic Proteins as a Basis for Changes in the Level of Primary Cellular Thermoresistance.- 3.1 Are the Shifts in Cellular Thermoresistance Accompanied by Alteration of the Cellular Resistance to Other Injurious Agents ?.- 3.2 Changes in Protein Thermostability Caused by Isolation of the Proteins From Cells.- 3.2.1 Modificational Variations of Protein Thermostability.- 3.2.1.1 Plants.- 3.2.1.2 Animals.- 3.2.1.3 Microorganisms.- 3.2.1.3 Summary.- 3.2.2 Genotypic Variations in Thermostability of Proteins.- 3.2.2.1 Plants.- 3.2.2.2 Animals.- 3.2.2.3 Microorganisms.- Summary.- 4. Adaptive Modifications of Conformational Flexibility of Macromolecules as a Basis for Changes of the Protein Thermostability.- 4.1 The Correlation Between Thermostability of Proteins and the Environmental Temperature Conditions of a Species' Life Cannot be Explained by an Adaptive Significance of the Level of Thermostability.- 4.2 A Hypothesis of the Adaptive Significance of a Correspondence of the Conformational Flexibility Level of the Protein Molecules to the Environmental Temperature Conditions of Species' Life.- 4.2.1 Conformational Changes of the Functioning Protein Macromolecules.- Summary.- 4.2.2 Effects of Temperature on the Conformation of Protein Macromolecules.- Summary.- 4.2.3 Adaptive Changes of the Conformational Flexibility of Protein Molecules With Changes in the Environmental Temperature.- 4.2.4 Thermostability of the Protein as an Indirect Indicator of the Conformational Flexibility of Protein Macromolecules.- 4.2.5 Conformational Flexibility of Protein Molecules and Adaptation of Organisms to the Environmental Temperature in Phylogenesis.- 4.2.6 Conformational Flexibility of Protein Molecules and Reactive Changes in the Primary Thermostability of Cells.- Summary.- 4.3 The Level of Conformational Flexibility of Protein Molecules and Their Resistance to Non-Thermal Agents.- 4.3.1 Non-Thermal Denaturants.- 4.3.2 Proteinases.- Summary.- 5. The Plausible Points of Application of the Natural Selection During Alteration of a Correspondence Between the Level of Conformational Flexibility of Protein Molecules and the Temperature Ecology of a Species.- 5.1 Activation Energy.- 5.2 Affinity of Enzymes to Substrates, the Michaelis Constant.- 5.3 A Temperature Optimum for Enzyme Activity.- Summary.- 5.4 Lifetime of Proteins in the Cell.- Summary.- 6. Plausible Mechanisms of Regulation of the Level of Conformational Flexibility of Proteins.- 6.1 Modificational Changes of the Conformational Flexibility of Protein Macromolecules.- 6.1.1 Heat Hardening of Plant Cells.- 6.1.1.1 Principle Features of the Mechanism Responsible for Heat Hardening.- 6.1.1.2 Action of Anti-Denaturants on Proteins and Cells.- 6.1.1.3 Suppositions About the Biochemical Mechanism Responsible for Heat Hardening of Cells.- 6.1.2 Other Types of Modificational Changes of Conformational Flexibility of Protein Molecules.- Summary.- 6.2 Genotypic Changes of the Conformational Flexibility of Protein Molecules.- 6.2.1 Some Information Concerning the Genetics of Thermostability.- 6.2.2 Mechanisms of Genotypic Changes of the Conformational Flexibility of Protein Molecules.- Summary.- 7. Thermostability of Nucleic Acids and the Temperature Environment of Species' Life.- Summary.- 8. Saturation of Fatty Acids and the Temperature Conditions of Life.- Summary.- Epilogue.- References.