Abbreviated Nomenclature of Synthetic Polypeptides (Polymerized Amino Acids) *

The numerous studies on the physical, chemical, and biological properties of synthetic polypeptides have brought with them different ways of describing, in abbreviated form, these products whose structures are often incompletely known. The use of a variety of nomenclatures complicates the literature; hence, a consistent and clearly defined system for naming such polypeptides is desirable. The proposals set forth here, which represent the consensus of many discussions and suggestions, should aid in systematizing the nomenclature of a wide variety of synthetic polypeptides. These proposals are based in large part on the abbreviated nomenclature devised by Gill (2) and by Sela (3) and others. They utilize the symbols and conventions set forth in Section 2 of “Revised Tentative Rules for Abbreviations and Symbels of Chemical Names of Special Interest in Biological Chemistry” (4) and in “Abbreviated Designation of Amino Acid Derivatives and Peptides” (5), and they add only those terms or conventions needed for the specification of polymers but not encompassed by these schemes. The symbols and conventions of the previous “Tentative Rules” (4, 5) used in this nomenclature system are summarized as follows. The symbols of the amino acid residues and their derivatives or modifications are those indicated in the “Tentative Rules” (4, 5) or formulated according to the principles set out in them. Hyphens or commas between the symbols for residues or groups of residues indicate known or unknown sequence, respectively, and involve only the α‐NH 2 and α‐COOH groups (the peptide link). Commas may be omitted when other symbols ( e.g. subscripts or superscripts) separate symbols in unknown sequences. Vertical strokes indicate covalent bonds involving functional groups or the remaining H‐atom of the peptide bond, depending upon their placement (5). L‐Amino acids and α‐peptide links, read from left (NH 2 terminus) to right (COOH terminus), are assumed unless indicated otherwise (4, 5).