Resynthesis of cod insulin from its polypeptide chains and the preparation of cod-ox “hybrid” insulins

Wilson, S.; Dixon, Gordon H.; Wardlaw, A. C.

doi:10.1016/0006-3002(62)90228-7

Cited by 66 publications

(15 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Substitutions in positions 8, 9 and 10 of the A chain, which account for most of the immunological specificity of the insulin molecule (3)(4)(5)(6)(7), probably explain the lack of sensitivity of radioimmunoassay for chicken insulin in systems where mammalian insulins are used both as the antigen and as the radioactive tracer (8). On the other hand, studies of the biological activity of chicken insulin gave equivocal results.…”

mentioning

confidence: 99%

Chicken Insulin: Radioimmunological Characterization and Enhanced Activity in Rat Fat Cells and Liver Plasma Membranes

1974

View full text Add to dashboard Cite

Insulin was extracted from chicken pancreases and purified; its chemical, immunological and biological properties were investigated. The chicken insulin preparation appeared homogeneous on polyacrylamide gel electrophoresis and its amiho acid composition was similar to that previously described by others. Among 21 guinea pig antihuman, anti-bovine and anti-porcine insulin sera, only one anti-porcine and two anti-human insulin sera cross-reacted with chicken insulin to a large extent. With one of them, chicken and human insulins were equipoterit, on a weight basis, in competing with the binding of 131 I-human insulin. The use of 13l I-chicken insulin improved the sensitivity of the radioimmunoassay (0.02 ng of insulin/ml of incubation medium) and allowed measurement of chicken insulin within the physiological range of its plasma concentrations. Chicken insulin (40 fig/kg of body wt) lowered the blood glucose level by 25% in the chicken. In isolated rat fat cells, chicken insulin was 1.5-to 1.9-fold as potent as highly purified preparations of porcine insulin (27 IU/mg) in stimulating glucose oxidation. In rat liver plasma membranes, chicken insulin was 1.8->to 2.4-fold as potent as porcine insulin in competing with the binding of 125 I-porcine insulin, and 2.4-fold as potent as porcine insulin in competing with the binding of 125 I-chicken insulin to the insulin receptor sites. 125 I-chicken and l25 I-porcine insulins were degraded to the same extent by the .liver membranes. Therefore, the enhanced biological potency observed in the rat in vitro with chicken insulin can be entirely accounted for by an increased binding affinity for the insulin receptors. (Endocrinology 95: 1439(Endocrinology 95: , 1974

show abstract

mentioning

confidence: 99%

Chicken Insulin: Radioimmunological Characterization and Enhanced Activity in Rat Fat Cells and Liver Plasma Membranes

1974

View full text Add to dashboard Cite

show abstract

“…It is therefore likely that most of the iodine-labeled insulin used in the experimerits which were presented in this communication, had iodine attached to the tyrosincs at position 14 and/or 19. WILSON, DIxo~ and WA~m, AW [12] have presented evidence that antibodies directed to the A chain determinants are more effective in neutralizing biological insulin activity than antibodies directed to B chain determinants.…”

Section: -H-mentioning

confidence: 99%

Genetic differences of combining sites of insulin antibodies and importance of C-terminal portion of the A chain to biological and immunological activity of insulin

1966

View full text Add to dashboard Cite

“…There has been some conflict in the results. Wilson et al, 3 Meienhofer and Brinkhof,* and Katzen et a1.j all report yields of 10% or less when reduced insulin chains are reoxidized. However, Jiang et a1.6 report yields of 40-50%.…”

mentioning

confidence: 97%

Study of biological activity regenerated by the oxidation of fully reduced insulin

Pruitt¹,

Robison²,

Gibbs³

1966

Biopolymers

View full text Add to dashboard Cite

SynopsisVarious techniques for recombining the fully reduced A and B chains of insulin were studied. Best results were obtained from water solutions of the reduced chains allowed to oxidize by standing in air a t 3°C. and from metal-catalyzed oxidations under the same conditions but in 7.6M urea solutions. Average net regeneration of insulin was 6%, by weight, based on rat hemidiaphragm analysis for insulin activity. The theoretical yield for a random recombination of the A and B chains was calculated to be 3y6.The 50% yield of insulin (from the oxidation of reduced insulin thiosulfate) reported by Jiang et al. could not be confirmed.Anfinsen has suggested' that the unique set of side chain interactions available to a protein as a consequence of its unique amino acid sequence is responsible for the correct folding of peptide chains during protein synthesis.This model was based on the results obtained upon reduction and reoxidation of the disulfide bonds of ribonuclease.2 Anfinsen and his coworkers found that, under optimum condit'ons, more than 90% of the enzyme activity lost on reduction is restored by the oxidation.Similar experiments have been attempted with insulin, which has interchain as well as intrachain disulfide bonds. There has been some conflict in the results. Wilson et al.,3 Meienhofer and Brinkhof,* and Katzen et a1.j all report yields of 10% or less when reduced insulin chains are reoxidized. However, Jiang et a1.6 report yields of 40-50%.Valid generalization of Anfinsen's hypothesis to multichain proteins requires a careful specification of pertinent experimental variables, especially protein concentration. Failure under a wide variety of reaction conditions to regenerate the properties of the native protein in an amount exceeding that to be expected from a random recombination of chains would indicate possible inapplicability of the hypothesis to the protein under study.The present work wsts undertaken to examine the reoxidation of reduced

show abstract

Resynthesis of cod insulin from its polypeptide chains and the preparation of cod-ox “hybrid” insulins

Cited by 66 publications

References 6 publications

Chicken Insulin: Radioimmunological Characterization and Enhanced Activity in Rat Fat Cells and Liver Plasma Membranes

Chicken Insulin: Radioimmunological Characterization and Enhanced Activity in Rat Fat Cells and Liver Plasma Membranes

Genetic differences of combining sites of insulin antibodies and importance of C-terminal portion of the A chain to biological and immunological activity of insulin

Study of biological activity regenerated by the oxidation of fully reduced insulin

Contact Info

Product

Resources

About