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Biomedical subjects

F Bossa

Publications and source records attributed to F Bossa.

At least 127 records · Page 7Linked to original sources
PubMed1978

Primary structure of hemoglobin from trout (Salmo irideus). Amino acid sequence of alpha chain of Hb trout I.

The amino acid sequence of the alpha chain of the hemoglobin component of trout's blood which is devoid of heterotropyc phenomena, i.e. Hb trout I, is presented. The sequence has been determined by analyzing the soluble tryptic peptides obtained from the whole globin and the peptides obtained after redigesting the insoluble 'core' with chymotrypsin. Alignment of the peptides with the structure of human as well as carp and Catostomus clarkii alpha chains shows that Hb trout I alpha chain differs from the corresponding human protein by 43% amino acid substitutions and from the two other fish by 34.5% and 33.1%, respectively. Further comparison of sequence data available for the N-terminal region suggests that the divergence between Hb trout I and IV, the other major hemoglobin component of trout's blood, is greater than that found between each trout hemoglobin and the other two fishes (carp and C. clarkii.).

Amino Acid Sequence↗
PubMed1977

Low molecular weight peptides controlling transcription are present in the calf thymus chromatin structure.

A calf thymus peptide fraction controlling DNA and chromatin template has been purified by DNA-cellulose and Dowex 50 WX2 chromatography and its amino acid composition determined. The active peptide fraction can be extracted in high pH buffer from calf thymus native chromatin previously deproteinized by chloroform-isamyl alcohol and phenol. These data demonstrate that the thymic peptide(s) is (are) a chromatin protein constituent strongly linked to DNA. The specificity in association of the peptide(s) to DNA has also been considered.

Animals↗
PubMed1976

Serine transhydroxymethylase from rabbit liver. Sequence of anonapeptide at the pyridoxal-5'-phosphate-binding site.

The amino acid sequence of the coenzyme-binding site of serine transhydroxymethylase from rabbit liver has been determined. After reduction with NaBH4 and aminoethylation, a first sample of enzyme was digested with thermolysin and a single phosphopyridoxyl peptide was isolated. A second sample of similarly treated enzyme was digested with chymotrypsin and three phosphopyridoxyl peptides clearly originating from a unique coenzyme-binding site were isolated. Sequence analysis of these peptides indicate the following structure: Val-Val-Thr-Thr-His(Pxy)-Thr-Leu. Sequence homologies of the active site of various pyridoxalphosphate enzymes are discussed in terms of a possible catalytic role and of evolution of this class of proteins.

Amino Acid Sequence↗
PubMed1976

Large-scale purification and some properties of the mitochondrial aspartate aminotransferase from pig heart.

A method has been developed which allows isolation of 0.3--0.5 g of mitochondrial aspartate aminotransferase in five days starting from 10 pig hearts; the method does not involve initial preparation of mitochondria. Mitochondrial malate dehydrogenase and the cytoplasmic aspartate aminotransferase may conveniently be recovered from side fractions. The product mitochondrial aspartate aminotransferase is homogeneous as judged by various electrophoretic techniques and by N-terminal analysis. Crystals of the enzyme have been obtained both from concentrated, essentially salt-free, solutions and from solutions of ammonium sulphate. The amino acid composition, N and C-terminal amino acid sequences and subunit molecular weight have been determined; these characteristic properties are compared with those of the cytoplasmic isozyme from the same source.

Amino Acid Sequence↗
PubMed1976

The phosphopyridoxyl peptide from the mitochondrial aspartate aminotransferase of beef kidney.

The sequence around the coenzyme-binding lysine of mitochondrial aspartate amino-transferase from beef kidney was determined. The holoenzyme was treated with NaB3H4 and digested with thermolysin; the labelled peptide was isolated and its sequence proved to be identical with sequences around the coenzyme site from the same isoenzyme of different organs and animals (pig heart and sheep liver). The sequences of the phosphopyridoxyl peptides of the mitochondrial aspartate aminotransferases appear to be closely related to the corresponding peptides from the cytoplasmic isoenzymes.

Amino Acids↗
PubMed1975

The primary structure of aspartate aminotransferase from pig heart muscle. Digestion with a proteinase having specificity for lysine residues.

Carboxymethylated aspartate aminotransferase was digested with a proteinase claimed to be specific for lysine residues. Complete cleavage occurred at 12 of the 19 lysine residues in the protein, but at the remaining seven residues cleavage was either restricted or absent. In addition, cleavage was observed at three of the 26 arginine residues. These results are discussed with reference to the amino acid residues adjacent to points of complete or restricted cleavage. The complete primary structure of aspartate aminotransferase, based on these and other studies, is given. Evidence for the assignment of some acid and amide side chains has been deposited as Supplementary Publication SUP 50050 (11 pp.) at the British Library (Lending Division), Boston Spa, Wetherby, W. Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1975) 145, 5. The evidence for the assignment of residue 366 was less conclusive than for the other acid and amide side chains and is, therefore, given in the main paper.

Amino Acid Sequence↗