Search PubMed⌕ Search

Biomedical subjects

C A Vernon

Publications and source records attributed to C A Vernon.

At least 37 records · Page 2Linked to original sources
PubMed1978

On the mechanism of immunosympathectomy.

The effects in vivo and in vitro of the antiserum to mouse nerve growth factor (NGF) are independent of the presence of complement. These results are consistent with the view that the antiserum acts by neutralizing endogenous NGF.

Animals↗
PubMed1978

The structures of some peptides from bee venom.

The sequences are given of two peptides (secapin and melittin F) whose isolation from the venom of the common European honey bee (Apis mellifera) has previously been described [Gauldie et al. (1976) Eur. J. Biochem. 61, 369--376]. Some structural studies on the known peptide 401 (MCD peptide) are described. The positions of the two disulphide bridges in peptide 401 have been determined by (an essentially) novel method.

Amino Acid Sequence↗
PubMed1977

Immunogenic contaminants in mouse nerve-growth factor.

Experiments are described that confirm the presence of gamma-globulin in standard preparations of mouse nerve growth factor (7-S complex and beta subunit) and show that antibodies to this protein are present in horse antisera to the growth factor. These antibodies may be partially removed by adsorption with soluble antigen and totally removed by affinity chromatography on columns of insolubilised antigen. These procedures do not affect the potency of the antiserum in vitro or in vivo. Contaminating globulin may be removed from samples of the isolated beta subunit by gel filtration to give an immunochemically pure preparation which will permit more meaningful studies on nerve growth factor and its antiserum.

Animals↗
PubMed1976

An assessment of some of the methods available for the determination of molecular weights of proteins as applied to aspartate aminotransferase from pig heart.

The isopotential specific volume of cytoplasmic aspartate aminotransferase from pig heart was found to be 0.763 ml g-1 whereas the value of the apparent specific volume obtained by summation of contributions from each type of amino acid in the protein is 0.735 ml g-1. Use of the experimentally determined isopotential specific volume largely abolishes the discrepancy between a previously reported value of the molecular weight of the native (dimeric) enzyme and that of the enzyme subunit obtained from its primary structure (46300). A new non-empirical method based on quantitative N-terminal analysis involving radioisotope dilution is described for the determination of subunit molecular weight of proteins. The method is capable of considerable accuracy and sensitivity. Some of the methods available for the determination of molecular weights ans subunit compositions of proteins are discussed.

Amino Acid Sequence↗
PubMed1976

Immunological properties of nerve growth factors.

Antisera were raised against nerve growth factors isolated from mouse salivary gland and five venoms representative of the three main families of poisonous snakes. Immunochemical cross-reactivity was assessed from the ability of the antisera to inhibit the biological activities of the heterologous antigens. The high and low molecular weight forms of the salivary gland factors were found to be immunologically identical but distinct from the snake venom factors. The snake venom factors, on the other hand, were immunologically closely related to each other but not identical.

Animals↗
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↗
PubMed1975

Effects of nerve growth factors from mouse salivary glands and snake venom on the sympathetic ganglia of neonatal and developing mice.

1. Quantitative histological analysis has been made of the effects of nerve growth factor (NGF) from mouse submaxillary gland and from the venom of Vipera russelli on superior cervical ganglia of neonatal mice. 2. The hypertrophic and hyperplastic effects reported by other workers have been confirmed. 3. The hypertrophic effect arises from an increase in the rate at which the sympathetic neurones attain their mature size. The size at maturity is never exceeded. 4. The hyperplastic effect arises from an increase in the rate of production of neurones from less differentiated cells. In the developmental period, the number of neurones can exceed that found at maturity. If injection of NGF is discontinued the excess neurones disappear. 5. If injection of NGF is continued to maturity, the excess number of neurones is maintained.

Animals↗
PubMed1974

Inducibility and some properties of the threonine dehydratase of sheep liver.

The threonine dehydratase extracted from sheep liver is in an essentially inactive form, referred to here as the precursor, but can be activated by incubation at high temperature in alkaline solution. A method for purification of the activated enzyme to a state approaching homogeneity has been devised. The activated enzyme catalyses the deamination of serine but rapidly loses activity during the process. The enzyme inactivated by incubation with serine can be reactivated under the same conditions as those described for the precursor, the kinetic parameters being the same in both cases. Individual sheep livers differ widely in their content of threonine dehydratase, and the possible role of dietary factors in this variability has been examined. The average amount of the enzyme in the livers of sheep fed on high-plant-protein diets did not differ significantly from that in livers obtained from slaughterhouses, but was higher than that in livers from animals fed only on grass or normal concentrates. Large increases in enzyme concentration were, however, obtained when sheep were injected intraperitoneally with a protein hydrolysate. The enzyme from the livers of these sheep could be purified by the same technique and to the same specific activity as the enzyme from the livers of control sheep.

Animals↗