Almost two centuries ago proteins were recognized as the primary materials (proteios = primary) oflife, but the significance and wide role of peptides (from pepsis = digestion) in practically all life pro cesses has only become apparent in the last few decades. Biologi cally active peptides are now being discovered at rapid intervals in the brain and in other organs including the heart, in the skin of amphibians and many other tissues. Peptides and peptide-like compounds are found among toxins and antibiotics. It is unlikely that this process, an almost explosive broadening of the field, will come to a sudden halt. By now it is obvious that Nature has used the combination of a small to moderate number of amino acids to generate a great variety of agonists with specific and often highly sophisticated functions. Thus, peptide chemistry must be regarded as a discipline in its own right, a major branch of biochemistry, fairly separate from the chemistry of proteins. Because of the important role played by synthesis both in the study and in the practical preparation of peptides, their area can be considered as belonging to bio-organic chemistry as well. The already overwhelming and still increasing body of know ledge renders an account of the history of peptide chemistry more and more difficult. It appears therefore timely to look back, to take stock and to recall the important stages in the development of a new discipline."

During the past few decades we have witnessed an era of remarkable growth in the field of molecular biology. In 1950 very little was known ofthe chemical constitution of biological systems, the manner in which information was transmitted from one organism to another, or the extent to which the chemical basis of life is unified. The picture today is dramatically different. We have an almost bewildering variety of information detailing many different aspects oflife at the molecular level. These great advances have brought with them some breath-taking insights into the molecular mechanisms used by nature for replicating, distributing and modifying biological information. We have learned a great deal about the chemical and physical nature of the macro molecular nucleic acids and proteins, and the manner in which carbohydrates, lipids and smaller molecules work together to provide the molecular setting of living systems. It might be said that these few decades have replaced a near vacuum of informa tion with a very large surplus. It is in the context of this flood of information that this series of monographs on molecular biology has been organized. The idea is to bring together in one place, between the covers of one book, a concise assessment of the state of the subject in a well-defined field. This will enable the reader to get a sense of historical perspective what is known about the field today - and a description of the frontiers of research where our knowledge is increasing steadily.

Generations of chemists have learned the synthesis methods of organic chemistry from this book with rules for preparing simple organic specimens. These rules never become obsolete. Prof. Dr. Ralf Steudel, TU Berlin"

The slowly acting amatoxins bind to the DNA dependent nucleoplas- mic RNA polymerase B (II) which is responsible for the transscription of m-RNA. This enables one to discriminate between form Band polymerase A (I), the enzyme catalyzing r-RNA synthesis, and to recognize all bio- logical events depending on m-RNA synthesis (protein synthesis after hormonal stimulation, growth of certain virus species etc.). Also with the amatoxins is the affinity for the receptor dependent on the conformation, visible by ORD and CD. All of the toxic derivatives are inhibitory, whereas not all of the inhibitory ones are toxic. This descrepancy is, in part, resolved by the observation of nontoxic "amanullins" dissociating more than ten times fast er from the enzyme than toxic ones. The quickly acting phallotoxins bind to a protein closely associated with the cytoplasmic membrane of the liver cell so causing the formation of microfilaments, the nature of which as actin has been proven by deco- ration with heavy meromyosin. Accordingly phallotoxins also bind to muscle actin which in presence of ADP and Mg++ immediately polym- erizes to a phallotoxin containing F -actin (Ph-actin). Ph-actin is also formed from F -actin by re action with phallotoxins. It differs from F -actin by its resistance against 0.6 M KI. Responsible for its toxic properties is the conformation of the molecule as can be followed by ORD and CD spectroscopy and the presence of a special methyl and hydroxyl group.