The amino acid sequence of fragment A, an enzymically active fragment of diphtheria toxin. II. The cyanogen bromide peptides.

Cyanogen bromide cleavage of Fragment A from diphtheria toxin at the four methionines present in each molecule resulted in five major peptides which were isolated and studied by sequence methods. These five peptides of 4, 11, 14, 63, and 101 residues account for all 193 residues in Fragment A and provide overlaps for the tryptic peptides from the maleylated protein. Two additional peptides were isolated and shown to be shorter forms (8 and 10 residues) of the COOH-terminal cyanogen bromide peptide (11 residues).     

The amino acid sequence of fragment A, an enzymically active fragment of diphtheria toxin. III. The chymotryptic peptides, the peptides derived by cleavage at tryptophan residues, and the complete sequence of the protein.

Fragment A (21,145 daltons in its longest known form) may be derived from diphtheria toxin (60,000 daltons) by mild tryptic digestion and reduction. Purified Fragment A consists of a mixture of 3 molecules of 190, 192, and 193 residues; the first 190 residues are in common and correspond to the NH2-terminal region the toxin. All three species of Fragment A are active in catalyzing ADP ribosylation of elongation factor 2, an essential component of protein synthesis. This reaction inactivates the factor and is responsible for the toxin's action in inhibiting protein synthesis in animal cells. It is believed that Fragment A or similar enzymically active fragments released into the cytosol of toxin-treated cells mediate this inhibition. The complete amino acid sequence of Fragment A has been determined from 32 chymotryptic peptides, three peptides derived by chemical cleavage of Fragment A at its 2 tryptophan residues, five cyanogen bromide peptides, and six tryptic peptides from the maleylated protein.     

The complete amino acid sequence of diphtheria toxin fragment B. Correlation with its lipid-binding properties

The complete amino acid sequence of fragment B from diphtheria toxin has been determined. The polypeptide chain was split with cyanogen bromide, o-iodosobenzoic acid, clostripain and trypsin; all amino acid sequence analyses were made by automated Edman degradation. Fragment B, which corresponds to the carboxy terminus of the toxin molecule, contains 342 amino acids and has an Mr of 37240. The proposed amino acid sequence fully confirms the structure recently deduced from the nucleotide sequence of the structural gene. The complete sequence is analyzed in relationship with the role of fragment B in the transfer of diphtheria toxin fragment A from the extracellular medium into the cell cytoplasm.     

Characterization of tryptic peptides from porcine haptoglobin light chain and an amino acid sequence.

The tryptic peptides derived from porcine haptoglobin light chains have been separated and characterized by composition, chromatography, electrophoretic mobility, and partial sequencing. Depending on homology with the corresponding human polypeptide, the amino acid sequence of the chain is proposed. Twenty differences from the human chain are indicated in the total of 84 residues.     

The amino acid sequence of Neurospora NADP-specific glutamate dehydrogenase. The tryptic peptides.

The NADP-specific glutamate dehydrogenase of Neurospora crassa was digested with trypsin, and peptides accounting for 441 out of the 452 residues of the polypeptide chain were isolated and substantially sequenced. Additional experimental detail has been deposited as Supplementary Publication SUP 50052 (11 pages) with the British Library (Lending Division), Boston Spa, Wetherby, W. Yorkshire LS23 7BQ, U.K., from whom copies may be obtained under the terms given in Biochem J. (1975) 145, 5.     

The amino acid sequence of the tryptic peptides isolated from dogfish M4 lactate dehydrogenase.

The peptides which result from treatment of the S-[14C]carboxymethyl derivative of dogfish M4 lactate dehydrogenase (EC 1.1.1.27) with trypsin have been isolated and their sequences have been elucidated. Each identical subunit has a molecular weight of 36,000 and on the basis of the amino acid composition 40 unique tryptic peptides are anticipated. Thirty-seven of these peptides have been isolated and have been completely characterized. The amino acid sequences of these peptides are presented.     

Complete amino acid sequence of human phosphoglycerate kinase. Isolation and amino acid sequence of tryptic peptides

As a part of the elucidation of the complete amino acid sequence of human phosphoglycerate kinase, 46 tryptic peptides, ranging in length from 1 to 26 residues, were isolated and characterized from the reduced and S-carboxymethylated enzyme. The isolated peptides were subjected to sequence analysis by the modified dansyl-Edman degradation procedure and automated Edman degradation technique. The results, together with the data on cyanogen bromide peptides and two additional tryptic peptides from cyanogen bromide peptides reported in the accompanying paper, established the complete amino acid sequence of human erythrocyte phosphoglycerate kinase.     

Amino acid sequence in tryptic peptides of maleylated Micrococcus sp. n. histidine decarboxylase beta-polypeptide chain]

Maleilated histidine decarboxylase beta-polypeptide chain, containing 3 arginine residue, was hydrolysed by trypsin. 4 non-overlapping homogenous peptides were isolated, 3 of them containing one arginine residue and the 4th peptide being C-terminal fragment of beta-chain. beta-Polypeptide chain is found to consist of 78 amino acid residues and to have molecular weight of 8456. Primary structure of each peptide and their possible sequence in beta-chain are determined.     

The amino acid sequence of the tryptic peptides from actinidin, a proteolytic enzyme from the fruit of Actinidia chinensis.

The amino acid sequences of the tryptic peptides of the thiol proteinase actinidin from Actinidia chinensis were determined by the manual dansyl--Edman procedure. There are 12 tryptic peptides, which give a polypeptide chain of 220 residues with a mol.wt. of 23500. An alignment of the tryptic peptides was made by using the X-ray-crystallographic data of Baker [(1977) J. Mol. Biol. 115, 263--277] determined at 0.28 nm resolution on crystalline actinidin. Detailed evidence for the amino acid sequences of the tryptic peptides has been deposited as Supplementary Publication SUP 50083 (14 pages) at the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1978) 169, 5.     

Pre-proparathyroid hormone: analysis of radioactive tryptic peptides and amino acid sequence.

The amino acid sequence of bovine pre-proparathyroid hormone has been partially determined by analysis of the polypeptide labeled selectively with radioactive amino acids. Analysis of tryptic peptides containing methionine or lysine indicated that parathyroid hormone, proparathyroid hormone, and pre-proparathyroid hormone had several common peptides. Two lysine-containing peptides present in proparathyroid hormone but not in parathyroid hormone were also present in pre-proparathyroid hormone. In addition, pre-proparathyroid hormone contained several additional lysine- and methionine-containing peptides not present in parathyroid hormone or proparathyroid hormone. Analysis by repetitive Edman degradation of the polypeptide labeled with lysine, methionine, and other amino acids indicated that pre-proparathyroid hormone contained 25 additional amino acids at the amino terminus of proparathyroid hormone; the identities of 17 of the 25 amino acids have been established. An unusual feature found was the presence of methionyl-methionyl at the amino terminus and the presence of 5 methionines within the first 14 amino acids.