The role of the arginine-B22 residue in insulin action

Rose, Keith; Rees, Anthony R.; Drake, Christopher S.; Offord, Robin E.

doi:10.1042/bj1950765

Cited by 4 publications

(6 citation statements)

References 9 publications

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“…It has been reported that modification of R(B22) with a bulky group of the opposite charge does not alter the specific bioactivity of insulin ( 20 ) as in the case of R(B22)D substitution ( 21 ), which is naturally occurring in mole rats and guinea pigs ( 15 ). Similarly, the R(B22)E substitution has also been reported to retain insulin bioactivity ( 22 ).…”

Section: Introductionmentioning

confidence: 99%

Predisposition to Proinsulin Misfolding as a Genetic Risk to Diet-Induced Diabetes

et al. 2021

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and anti-proinsulin immunoblotting is shown below, highlighting the presence of aberrant disulfidelinked proinsulin complexes. B) Quantitation of islet proinsulin and insulin protein levels (each point an independent male animal) by Western blotting as in panel A (mean ± s.d.; * p < 0.05; ** p < 0.01). Supplement Fig. S2. Circulating proinsulin, and proinsulin-to-insulin ratio, from 11.5 week old HFD-fed Ins2-proinsulin-R(B22)E heterozygous males (pink symbols), superimposed onto the data reproduced from Figs 2G and H. Horizontal asterisks represent statistical differences (mean ± s.d.) along the X-axis (blood glucose); vertical asterisks indicate statistical differences along the Y-axis (proinsulin level, or proinsulin-to-insulin ratio). Supplement Fig. S3. Transmission electron micrographs of islets cells from the genotypes (and diet) included in this study. Random blood glucose at the time of euthanasia is indicated on each figure. Scale bars are shown on all figures. A) Typical β-cell from male WT mouse and Ins2proinsulin-R(B22)E heterozygote on normal chow diet (age 4 weeks). B) Another typical β-cell from the animals analyzed in panel A, at higher magnification to highlight ER and secretory granule morphology. C) β-cell from WT mouse fed a HFD for 6 weeks with organelles labeled on the figure. ISG = immature secretory granule. VTCs are a pre-Golgi compartment. D) Upper left image: low-power of islet from HFD-fed male Ins2-proinsulin-R(B22)E heterozygote (age 6 weeks). "Cell A and B" are β-cells; "Cell C" is an α-cell. Note that Cell B is poorly granulated.

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Section: Introductionmentioning

confidence: 99%

Predisposition to Proinsulin Misfolding as a Genetic Risk to Diet-Induced Diabetes

et al. 2021

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“…Proinsulin-R(B22)E (Fig. 1A) should lead to bioactive insulin (20)(21)(22), yet may not necessarily support efficient proinsulin protein folding (16; 26-29). We first examined the behavior of recombinant human proinsulin-R(B22)E. Min6 pancreatic β-cells express their own endogenous mouse proinsulin, but we probed transfected cells, and media, with an antibody that recognizes only human proinsulin protein.…”

Section: Expression Of Recombinant Proinsulin-r(b22)ementioning

confidence: 99%

“…It has been reported that modification of R(B22) with a bulky group of the opposite charge does not alter the specific bioactivity of insulin (20) as in the case of R(B22)D substitution (21), which is naturally occurring in mole rats and guinea pigs (15); similarly, the R(B22)E substitution has also been reported to retain insulin bioactivity (22). Here, we've pursued the possible impact of proinsulin-R(B22)E expression in the β-cells of mice in which this variant is knocked into the Ins2 locus.…”

Section: Introductionmentioning

confidence: 99%

Predisposition to Proinsulin Misfolding as a Genetic Risk to Diet-Induced Diabetes

Alam

Arunagiri

Haataja

et al. 2021

Preprint

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Throughout evolution, proinsulin has exhibited significant sequence variation in both C-peptide and insulin moieties. As the proinsulin coding sequence evolves, the gene product continues to be under selection pressure both for ultimate insulin bioactivity and for the ability of proinsulin to be folded for export through the secretory pathway of pancreatic β-cells. The substitution proinsulin-R(B22)E is known to yield a bioactive insulin, although R(B22)Q has been reported as a mutation that falls within the spectrum of Mutant INS gene induced Diabetes of Youth (MIDY). Here we have studied mice expressing heterozygous (or homozygous) proinsulin-R(B22)E knocked into the Ins2 locus. Neither females nor males bearing the heterozygous mutation develop diabetes at any age examined, but subtle evidence of increased proinsulin misfolding in the endoplasmic reticulum is demonstrable in isolated islets from the heterozygotes. Moreover, males have indications of glucose intolerance and within a few week exposure to a high-fat diet, they develop frank diabetes. Diabetes is more severe in homozygotes, and the development of disease parallels a progressive heterogeneity of β cells with increasing fractions of proinsulin rich/insulin-poor cells, as well as glucagon-positive cells. Evidently, sub-threshold predisposition to proinsulin misfolding can go undetected, but provides genetic susceptibility to diet-induced β-cell failure.

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“…The electrophoresis was performed on strips of cellulose acetate in a urea-containing borate buffer, pHa8.0, staining with Ponceau l, as described previously (Rose et al, 1981). FF indicates the position reached by the dye Cyanol FF, applied at the origin.…”

Section: Wsmentioning

confidence: 99%

Rapid preparation of human insulin and insulin analogues in high yield by enzyme-assisted semi-synthesis

Rose¹,

Pury²,

Offord³

1983

Biochemical Journal

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Reaction conditions are described that permit the enzyme-assisted semi-synthetic replacement of residue B30 of pig insulin (or of analogue) to proceed in very high yield in 2 h or less. Immobilized trypsin may be used as catalyst, and excess amino acid ester may be recycled after a simple extraction. Alanine-B30 may be replaced by a variety of nucleophiles, including threonine O-t-butyl ether t-butyl ester, in which case the yield of crude product is about 99%. De-protection of the B30 threonyl ester analogue of insulin thus formed then affords human insulin in an overall yield of about 92%, based on pig starting material. The product has full biological potency, as determined by depression of blood glucose concentration in rats, and showed the expected behaviour on radioimmunoassay.

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The role of the arginine-B22 residue in insulin action

Cited by 4 publications

References 9 publications

Predisposition to Proinsulin Misfolding as a Genetic Risk to Diet-Induced Diabetes

Predisposition to Proinsulin Misfolding as a Genetic Risk to Diet-Induced Diabetes

Predisposition to Proinsulin Misfolding as a Genetic Risk to Diet-Induced Diabetes

Rapid preparation of human insulin and insulin analogues in high yield by enzyme-assisted semi-synthesis

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