Molecular Characterisation of Long-Acting Insulin Analogues in Comparison with Human Insulin, IGF-1 and Insulin X10Report as inadecuate




Molecular Characterisation of Long-Acting Insulin Analogues in Comparison with Human Insulin, IGF-1 and Insulin X10 - Download this document for free, or read online. Document in PDF available to download.

Aims-Hypothesis

There is controversy with respect to molecular characteristics of insulin analogues. We report a series of experiments forming a comprehensive characterisation of the long acting insulin analogues, glargine and detemir, in comparison with human insulin, IGF-1, and the super-mitogenic insulin, X10.

Methods

We measured binding of ligands to membrane-bound and solubilised receptors, receptor activation and mitogenicity in a number of cell types.

Results

Detemir and glargine each displayed a balanced affinity for insulin receptor IR isoforms A and B. This was also true for X10, whereas IGF-1 had a higher affinity for IR-A than IR-B. X10 and glargine both exhibited a higher relative IGF-1R than IR binding affinity, whereas detemir displayed an IGF-1R:IR binding ratio of ≤1. Ligands with high relative IGF-1R affinity also had high affinity for IR-IGF-1R hybrid receptors. In general, the relative binding affinities of the analogues were reflected in their ability to phosphorylate the IR and IGF-1R. Detailed analysis revealed that X10, in contrast to the other ligands, seemed to evoke a preferential phosphorylation of juxtamembrane and kinase domain phosphorylation sites of the IR. Sustained phosphorylation was only observed from the IR after stimulation with X10, and after stimulation with IGF-1 from the IGF-1R. Both X10 and glargine showed an increased mitogenic potency compared to human insulin in cells expressing many IGF-1Rs, whereas only X10 showed increased mitogenicity in cells expressing many IRs.

Conclusions

Detailed analysis of receptor binding, activation and in vitro mitogenicity indicated no molecular safety concern with detemir.



Author: Bo F. Hansen , Tine Glendorf, Anne C. Hegelund, Anders Lundby, Anne Lützen, Rita Slaaby, Carsten Enggaard Stidsen

Source: http://plos.srce.hr/



DOWNLOAD PDF




Related documents