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Biomedical subjects

T C Elleman

Publications and source records attributed to T C Elleman.

46 records · Page 3Linked to original sources

Isolation, characterization and pathology of the toxin from a Microcystis aeruginosa (= Anacystis cyanea) bloom.

The nature of the toxicity of a bloom of blue-green alga, M. aeruginosa (= Anacystis cyanea), that occurred in a man-made lake was investigated. Crude algal bloom extracts were toxic to laboratory mice when injected intraperitoneally. The lethal dose (LD100) of these extracts was 15-30 mg of lyophilized algal bloom per kilogram body weight. The toxin was purified by a procedure that included ammonium sulphate fractionation, solvent extraction, acid precipitation, Sephadex G25 and DEAE-Sephadex chromatography, and high-voltage electrophoresis at pH 6.5. The preparation gave a single spot on high-voltage electrophoresis at pH 9.0, had no free amino group, and was characterized by a simple amino acid composition of equimolar quantities of L-methionine, L-tyrosine, D-alanine, D-glutamic acid, erythro beta-methyl aspartic acid and methylamine. The LD50 for the purified toxin was estimated to be 0.056 mg/kg of mice, and the approximate LD100 is 0.070 mg/kg, based on the total material found from amino acid analysis. Parenteral administration of the purified toxin to mice produced extensive liver lobular haemorrhage and death within 1-3 h. Repeated inoculation of sublethal doses daily over some weeks produced progressive hepatocyte degeneration and necrosis and the development of fine hepatic fibrosis.

Amino Acids↗

Amino acid sequence of the smaller subunit of conglutin gamma, a storage globulin of Lupinus angustifolius.

The amino acid sequence of the smaller subunit of conglutin gamma, the simplest of the three globulins from the seeds of Lupinus angustifolius cv. Uniwhite, has been determined. The subunit was homogeneous and contained 154 amino acid residues, including five sulphur-containing amino acids--a considerably higher content than is found in most other legume storage proteins. There was no indication of the complexity experienced in studies of many other legume storage proteins. This is perhaps the first sequence of a subunit of a legume storage protein to be determined.

Amino Acid Sequence↗

Aminopeptides of pea.

Studies of crude extracts of pea seeds (Pisum sativum, var. Green feast) revealed the presence of three enzymes that hydrolyse the amide bond of aminoacyl beta-naphthylamides. They differ in their specificity towards the aminoacyl moiety; one is proline-specific, whereas the other two hydrolyse the beta-naphthylamides of primary amino acids. Of the latter, one is highly specific for hydrophobic aminoacyl residues whereas the other has a broader, somewhat complementary specificity, showing preferential hydrolysis of non-hydrophobic aminoacyl residues. These latter two aminoacyl-beta-naphthylamidases have been separated and partly characterized with regard to substrate specificity and antagonism by inhibitors. Both are true aminopeptidases, requiring the presence of a free amino group and hydrolysing the amide bonds of amino acid amides, dipeptides and oligopeptides consecutively from the N-terminal end.

Aminopeptidases↗

The preparation and properties of a group of proteins from the high-sulphur fraction of wool.

A method is reported for the preparation of a group of three proteins from the S-carboxymethylated high-sulphur fraction of wool. These proteins have been partially characterized by their tryptic peptides. All have similar structural features and show an interesting homology within the group and some similarities of sequence with a different group of wool high-sulphur proteins. The evidence for the sequence of some of the peptides is given in a supplementary paper that has been deposited as Supplementary Publication 50008 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1972) 126, 5.

Amino Acid Sequence↗

The amino acid sequence of protein SCMK-B2C from the high-sulphur fraction of wool keratin.

1. The amino acid sequence of a protein from the reduced and carboxymethylated high-sulphur fraction of wool has been determined. 2. The sequence of this S-carboxymethylkerateine (SCMK-B2C) of 151 amino acid residues displays much internal homology and an unusual residue distribution. Thus a ten-residue sequence occurs four times near the N-terminus and five times near the C-terminus with few changes. These regions contain much of the molecule's half-cystine, whereas between them there is a region of 19 residues that are mainly small and devoid of cystine and proline. 3. Certain models of the wool fibre based on its mechanical and physical properties propose a matrix of small compact globular units linked together to form beaded chains. The unusual distribution of the component residues of protein SCMK-B2C suggests structures in the wool-fibre matrix compatible with certain features of the proposed models.

Amino Acid Sequence↗

The amino acid sequence of protein SCMK-B2A from the high-sulphur fraction of wool keratin.

1. The amino acid sequence of protein SCMK-B2A, a reduced and S-carboxymethylated protein from the high-sulphur fraction of wool, has been determined. 2. This protein of 171 amino acid residues displays both a high degree of internal homology and extensive external homology with other members of the SCMK-B2 group of proteins. 3. Evidence is presented which suggests that the SCMK-B2 group of proteins are produced by separate non-allelic genes.

Amino Acid Sequence↗

The amino acid sequences of cysteic acid-containing peptides from performic acid-oxidized ovotransferrin.

1. The half-cystine content of ovotransferrin, measured as cysteic acid, was 31mol/80000g of protein. 2. The amino acid sequences of cysteic acid-containing peptides from performic acid-oxidized ovotransferrin were studied. 3. 34 unique cysteic acid residues were identified. 4. It is concluded that hen ovotransferrin does not consist of two identical halves or subunits.

Amino Acid Sequence↗