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A C Server

Publications and source records attributed to A C Server.

23 records · Page 2Linked to original sources
PubMed1976

Characterization of the gamma subunits of the 7S nerve growth factor complex.

The gamma subunits of the 7S nerve growth factor complex (7S NGF) display arginine esteropeptidase activity. By varying the conditions of electrophoresis in acrylamide gel, it has been demonstrated that the gamma-subunit fraction of 7S NGF contains five different proteins, in contrast to the three (gamma1, gamma2, and gamma3) originally described (Smith, A.P., Varon, S. and Shooter, E.M. (1968), Biochemistry 7, 3259-3268); the gamma1 and gamma2 subunits, previously thought to be single species, can each be resolved into two components. The two components of the gamma1 subunit have the same isoelectric point, as do the two components of the gamma2 subunit. The distribution of protein among the two components of each of the gamma1 and gamma2 subunits varied from preparation to preparation. Moreover, a shift in the distribution for the gamma1 subunit was accompanied by a parallel shift for the gamma2 subunit. All of the different gamma proteins have the same molecular weight. On the basis of the molecular weights of the peptide chains of the gamma subunits and of the species which are formed by cross-linking with dimethyl suberimidate, it was concluded, that both the gamma1 and gamma2 subunits contain one species with two peptide chains and another with three peptide chains, while the gamma3 subunit is a single species with three peptide chains. The results also suggest that two of the chains in the three-chain species are derived, by proteolytic cleavage, from the larger chain in the two-chain species.

Amino Acids↗
PubMed1976

Modification of the epidermal growth factor affecting the stability of its high molecular weight complex.

The epidermal growth factor (EGF) can be isolated from the submaxillary gland of the adult male mouse as part of a high molecular weight complex (HMW-EGF). This complex can be reversibly dissociated into its subunits, EGF AND EGF-binding protein, an arginine esteropeptidase (Taylor, J. M., Cohen, S., and Mitchell, W. M. (1970) Proc. Natl. Acad. Sci. U. S. A. 67, 164-171). The COOH-terminal arginine residue of EGF was quantitatively removed by digestion with carboxypeptidase B...

Amino Acids↗
PubMed1976

Comparison of the nerve growth factor proteins from cobra venom (Naja naja) and mouse submaxillary gland.

The nerve growth factors (NGF's) isolated from cobra venom (Naja naja) and mouse submaxillary gland are closely related proteins. They are structurally similar in that about 60% of their amino acid residues are identical (Hogue-Angeletti, R. A., Frazier, W. A., Jacobs, J. W., Niall, H.D., and Bradshaw, R. A. (1976), Biochemistry, preceding paper in this issue). They are functionally similar in that they both elicit maximum neurite outgrowth from chick embryonic dorsal root ganglia at the same protein concentration. However, the extent of the response is not as great with Naja naja NGF. The cobra NGF has an affinity close to that of mouse NGF for a major proportion of the specific NGF receptors on cells from dissociated embryonic dorsal root ganglia. Despite these similarities there are differences which can be detected between the two proteins. High concentrations of Naja naja NGF will not displace approximately 20% of the binding of mouse NGF to specific NGF receptors. Moreover, Naja naja NGF shows limited cross-reactivity with antiserum to mouse NGF in a competition radioimmunoassay, consistent with the extent of its amino acid sequence homology with mouse NGF. Naja naja NGF does not interact with the alpha- and gamma-subunits of 7S NGF to form a high molecular weight complex. In this behavior it resembles a modified form of mouse NGF which, like Naja naja NGF, lacks COOH-terminal arginine residues.

Amino Acids↗
PubMed1976

Comparison of the arginine esteropeptidases associated with the nerve and epidermal growth factor.

The nerve growth factor (NGF) and the epidermal growth factor (EGF) of the male mouse submaxillary gland are found in association with arginine esteropeptidases. These enzymes, the gamma subunits of 7 S NGF and the EGF-binding protein, respectively, have similar molecular weights, amino acid compositions, and substrate specificities (Greene, L. A., Shooter, E. M., and Varon, S. (1969) Biochemistry 8, 3735-3741; Taylor, J.M., Mitchell, W. M., and Cohen, S. (1974) J. Biol. Chem. 249, 21-8-2194). Although on the basis of molecular weight, the EGF-binding protein has a peptide chain composition similar to that of the gamma3 subunit, it does not have the same isoelectric point nor electrophoretic properties as the subunit. In urea, its isoelectric point differs from those of the gamma1, gamma2, and gamma3 subunits. The EGF-binding protein has antigenic determinants not shared by the gamma subunits and vice versa. It also fails to replace the gamma subunits in the formation of 7 S NGF points to the specificity of this complex and supports the hypothesis that the nerve and epidermal growth factors are generated from larger precursors by the proteolytic action of their respective arginine esteropeptidases.

Amino Acids↗