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P J Hollins

Publications and source records attributed to P J Hollins.

7 recordsLinked to original sources
PubMed1979

Alteration in the immunochemical dominance of determinants following the chemical modification of ox insulins: implications for the structure of the ox insulin monomer in solution.

Insulins of differing species, together with chemically modified insulins, were used in cross-reactivity experiments employing selected antisera raised to ox insulin in the Harley guinea-pig. The immunogen had been administered as a water-in-oil emulsion, using H. pertussis vaccine as adjuvant. Antibody was generated by determinants in the C-terminus of the B chain plus the adjacent N-terminus of the A chain, in the central core of the A chain (A8-A14 region) and in its anti-parallel N-terminus of the B chain. From this antibody pool chemically modified ox insulin selected antibody to unaltered determinants. The immunochemical data were compatible with monomeric ox insulin being immunogenic, the immunogen perhaps being recognized by the immune system in the form of the Molecule-II rather than the Molecule-I of the dimer pair (as originally suggested by X-ray crystallographic data).

Amino Acids↗
PubMed1978

Haptenic antibody induced by N-phthaloylated ox insulin in the Hartley guinea-pig.

Female Hartley guinea-pigs were immunized with N-phthaloylated ox insulin (96% NA1,NB1,NB29-triphthaloyl ox insulin) using H. pertussis as adjuvant. Haptenic antibody, which was found in antisera taken 20 days after secondary immunization, was assessed for cross-reaction with a series of N-acylated ox insulins. Cross-reaction readily occurred between haptenic antibody and the partial hapten-bearing antigens, NA1-monophthaloyl and NB1-monophthaloyl ox insulins. The immunochemical data suggested that the NA1-glycyl hapten and the NB1-phenylalanyl hapten were both acting as immune determinants for B-lymphocytes, and the determinant competition was taking place between contralateral facets of the principal immunogen, NA1,NB1,NB29-triphthaloyl ox insulin. The data was also consistent with the view that the overall tertiary structure of N-acylated insulins may be very similar to that of their native insulin, the addition of hapten groups having produced only localized areas of structural perturbation.

Animals↗
PubMed1976

Aspects of the secondary antibody response to ox insulin in the Hartley guinea-pig; the use of chemically modified ox insulin to delineate the antigenic determinants of ox insulin.

The use of a quinea-pig model to study the immunogenicity of the insulin molecule is presented. The Hartley guinea-pig has been shown consistently to form antibody to ox insulin, when given in a water-in-oil emulsion containing pertussis vaccine as adjuvant. After log transformation of standardized antibody titres to iodo-ox insulin, a valid statistical comparison of the antibody response to different ox insulin preparations could be made. Antibody cross-reacting with ox insulin, but not iodo-ox insulin, was also detected. The quantity of one type of antibody was complementary to the other, an observation compatible with determinant competition having occurred during the immune response. From the results of cross-reactivity experiments using N-triacylated ox insulins and human insulin, it was shown that antibody cross-reacting with iodo-ox insulin had most probably been produced to a localized area of the molecule.

Animals↗
PubMed1976

Determinant competition during the immune response to N-acyl derivatives of ox insulin in the Hartley guinea-pig.

Subgroups of female Hartley guinea-pigs were immunized with N-carbamylated ox insulin, N-maleylated ox insulin, N-phthaloylated ox insulin, or with the crystalline ox insulin from which the N-acylated insulins had been prepared. The immunogens were administered in water-in-oil emulsions containing pertussis vaccine as adjuvant. Sera obtained 20 days after secondary immunization were assayed for their antibody titres to iodo-ox insulin and their insulin-binding capacities. The data were log transformed for statistical comparison. N-carbamylated ox insulin seemed to be as immunogenic as crystalline ox insulin and no specific carbamyl hapten antibody could be found. N-maleylated and N-phthaloylated ox insulins yelded significantly less antibody cross-reactingwith iodo-ox insulin, but produced a complementary quantity of specific maleyl and phthaloyl hapten antibody respectively. Thus it was shown that in the system used the immune response was partitioned between different determinants, ox insulin and its N-acylated derivatives being equipotent immunogens.

Acylation↗