A COMPARISON OF ANIMAL HEMOGLOBINS BY TRYPTIC PEPTIDE PATTERN ANALYSIS

The complete amino acid sequences (primary structure) of hemoglobins can, in principle, be determined by methods currently available. Although detailed studies of the primary structure of human and horse hemoglobins are in progress in several laboratories,(1) the methods are so laborious that complete sequences have not yet been established. Important questions in the realm of genetics and evolution require the immediate examination of the structure, primary and other, of many different hemoglobins. The application of methods that are quicker, though less informative and reliable, than the techniques required for complete sequence determination is therefore in order as a provisional means of securing useful information. Such a method is the analysis of peptide patterns obtained by combined paper electrophoresis and chromatography of tryptic hydrolysates of denatured hemoglobin.(2) Of particular interest are comparisons between hemoglobin components present in (a) organisms of one animal species at a given time in development, (b) organisms of one species at different stages of development, and (c) organisms of different species. The present paper is concerned exclusively with the last type of comparison. In order to scan the range of variation of hemoglobin structure throughout evolution, hemoglobins from a number of animals both closely and distantly related to man have been selected and compared as to tryptic peptide patterns with human hemoglobin A. Whole hemoglobin preparations from adult animals have been studied throughout. The problem of individual heterogeneity will be treated elsewhere

Collecting, Comparing, and Computing Sequences: The Making of Margaret O. Dayhoff’s Atlas of Protein Sequence and Structure, 1954–1965

Collecting, comparing, and computing molecular sequences are among the most prevalent practices in contemporary biological research. They represent a specific way of producing knowledge. This paper explores the historical development of these practices, focusing on the work of Margaret O. Dayhoff, Richard V. Eck, and Robert S. Ledley, who produced the first computer-based collection of protein sequences, published in book format in 1965 as the Atlas of Protein Sequence and Structure. While these practices are generally associated with the rise of molecular evolution in the 1960s, this paper shows that they grew out of research agendas from the previous decade, including the biochemical investigation of the relations between the structures and function of proteins and the theoretical attempt to decipher the genetic code. It also shows how computers became essential for the handling and analysis of sequence data. Finally, this paper reflects on the relationships between experimenting and collecting as two distinct ‘‘ways of knowing’’ that were essential for the transformation of the life sciences in the twentieth century