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Using automated stepwise Edman degradation of suitable overlapping peptides, the complete amino acid sequence of the 268 residue peptida α1-CB7 from calf skin collagen was determined. The preparation and ordering of the chymotryptic, tryptic and thermolytic peptides is described in the preceding paper. As shown previously for other peptides from the helical region of collagen, glycine appears in every third position and proline is present in high amount. Hydroxylation of proline to 4-hydroxyproline and lysine to hydroxylysine only occurred in the Y position of the tripeptide unit Gly-X-Y. Non-random distribution of other amino acids between the X and Y positions was also observed. [ABSTRACT FROM AUTHOR]

Chymotryptic cleavage of α1-CB6, the C-terminal CNBr peptide of the α1-chain from calf skin collagen, yields three peptides, designated C1 (positions 1-113), C2 (positions 114-196) and C3 (positions 197-217), respectively. The present paper describes the amino acid sequence of C2. It was determined exclusively by application of the automated Edman degradation. The entire peptide C2 as well as some of its tryptic and thermolytic peptides were subjected to this procedure. The helical portion of α1-CB6-C2 (positions 114-192) was found to consist of tripeptide units containing glycine in every third position, hence being typical of the collagen structure. The α1-chain of calf skin collagen contains a 3-hydroxyproline residue which was located in position 164 in the tripeptide unit Gly-3Hyp-4Hyp. This is the first case of a vertebrate collagen in which hydroxylation was found of a proline in position X of the tripeptide unit Gly-X-Y. The helical part of the α1-chain terminates in a five-fold repetition of the tripeptide Gly-Pro-Pro. The four C-terminal amino acids of C2 are already part of the nonhelical area at the end of the α1-chain which in addition comprises the entire peptide C3. [ABSTRACT FROM AUTHOR]

The complete sequence (153 amino acids) of horse heart myoglobin has been established. The sequence of a peptide isolated from chymotrypsin hydrolyzates of globin allowed to fill a gap in the tentative sequence previously proposed; this peptide was studied by means of pepsin hydrolysis, action of N-bromosuccinimide on histidyl bonds, and Edman degradation method associated with dansylation. After hydrolysis of globin by chymotrypsin treated by TLCK, the same major peptides were found as after hydrolysis by non-treated chymotrypsin. These peptides were identified by ionexchange resins and bidimensional paper chromatography, and also by the determination of their amino-acid composition. The suppression of secondary cuts explains the presence of new peptides, whose the composition and N-terminal Sequences were determined, it was then possible to confirm several sequences which could be previously deduced from the study of split products after cyanogen bromide treatment. The specificity of chymotrypsin towards certain types of peptide bonds is discussed. Horse myoglobin, as compared with sperm whale myoglobin, contains 18 differences: 17 substitutions and one inversion. The major part of the substitutions are located ih N- and C-terminal sequences: they are all punctiform, resulting from the replacement of only one base in each codon. [ABSTRACT FROM AUTHOR]