The rapid development and recent advances in this field seemed to justify a further meeting dealing primarily with protein interconversions and their biological significance rather soon after the first symposium of this kind, held under the direction of Professor G. BONSIGNORE of Genoa, in Santa Margherita Ligure, Italy, in May 1970. The proceedings of the Second International Symposium on Metabolic Interconversion of Enzymes, held in Rottach-Egern, in the Bavarian Alps, from October 27-30, 1971, under the auspices of the "Gesellschaft Deutscher N aturforscher und Arzte" bear witness to the high quality of the research reports and the lively discussions which ensued. There are contributions by a number of distinguished scientists and experts in the field who came from several European countries, Canada, Israel, Japan, the Soviet Union and the United States in order to participate in this symposium. We wish to express our sincere gratitude to the speakers for all their efforts. The main burden of the editorial work was carried by Dr. G. LOFFLER, Munich, ably as Dr. A. R. FERGUSON, Freiburg, Dr. R. H. HASCHKE, Wiirzburg, Dr. A. HASILlK, sisted by Freiburg, Dr. L. HEILMEYER Jr. , Wiirzburg, Dr. E. SIESS, Munich, and by the secretaries, Miss E. BAUER, Munich and Mrs. G. WEIDEMANN, Wiirzburg. To the publishers, Springer Verlag Berlin Heidelberg New York, and especially to Dr. H. MAYER-KAUPP, we are greatly indebted for their cooperation.

Welcoming Remarks

Metabolic Interconversion of Enzymes: Introductory Remarks
Comparative and Evolutionary Aspects of the Control of Phosphorylase
Electron Microscopy of Muscle Phosphorylases b and a
Discussion
Studies on Glycogen Phosphorylase in Solution and in the Crystalline State
Probing and Mapping the Pyridoxal 5?-Phosphate Site of Glycogen Phosphorylase
Association-dissociation Properties of NaBH4-reduced Phosphorylase b
The Mechanism of Action of Cyclic AMP in the Activation of Phosphorylase Kinase
Discussion
Phosphorylase a as a Glucose Receptor
Properties of Purified Glycogen Synthetase b from Liver
Discussion
The Mechanism of Activation of the Lac Operon
Discussion
Regulatory Mechanism of Enzyme Catabolism
Discussion
Interconversion of Two Forms of Leucyl-tRNA Synthetase
Discussion
Diphtheria Toxin-catalyzed Adenosine Diphosphoribosylation of Aminoacyl Transferase II from Rat Liver
Discussion
Regulation of Transcription by T4 Phage Induced Chemical Alteration and Modification of Transcriptase (EC2.7.7.6)
Discussion
On the Mechanism of Action and Metabolic Control of the Multifunctional Enzyme Complex that Catalyzes Adenylylation and Deadenylylation of Escherichia Coli Glutamine Synthetase
Inactivation of Glutamine Synthetase in Intact E. coli Cells
Studies on the Mechanism of the ATP: Glutamine Synthetase Adenylyltransferase Reaction
The Role of Enzyme Inactivation in the Regulation of Glutamine Synthesis in Yeast: in vivo Studies Using 15NH3
Discussion
Molecular Aspects of the Regulation of the Mammalian Pyruvate Dehydrogenase Complex
Regulation of the Mammalian Pyruvate Dehydrogenase Complex: Physiological Aspects and Characterization of PDH-Phosphatase from Pig Heart
Discussion.-Enzyme-dependent Activation of P ruvate Formate-lyase of, Escherichia coli
Discussion
Lactose Synthetase: Structure and Function
UDP-glucose: D-fructose-6-phosphate 2-glucosyltransferase: Metabolic Control of the Enzyme Activity
Discussion
Mechanism of Interaction between Arginase and Ornithine Transcarbamoyl Transferase of Saccharomyces cerevisiae
Discussion
Enzymatic Modification of Basic Chromosomal Proteins in Developing Trout Testis
Discussion
Active Site-directed Side Chain Modification
Discussion
Metabolic Interconversion: of Enzymes: Relation to the Hysteretic Response
Discussion
Why Are Enzymes Interconvertible?
General Discussion
List of Participants.