In Vitro Nitrosation of Insulin A- and B-Chains

Abstract

The physiological roles of insulin and nitric oxide (NO) have been recently recognized by several studies. A diversity of chemical modifications of insulin is reported both in vivo and in vitro. S-nitrosation, the covalent linkage of NO to cysteine free thiol is recognized as an important post-translational regulation in many proteins. Here we report the in vitro synthesis of an S-nitrosothiol of bovine insulin A- and B-chains. These compounds were characterized by their HPLC chromatographic behavior, monitored by UV visible spectroscopy and electron spray ionization mass spectrometry. The experimental results indicate that each A- and B-chain were S- nitrosated with only one NO group. Stability and solubility of these synthesized derivatives is described for physiological purposes. In this work, nitroso A- and B-chains of insulin were synthesized in vitro in order to better understand the possible interactions between insulin and NO that may be involved in the etiology of insulin resistance.

Risk of postprandial insulin resistance: The liver/vagus rapport

“…This suggests that RSNO has a role in promoting peripheral insulin-stimulated glucose uptake; and that negative feedback may be present if the RSNO concentration reaching the portal vein is too high. If the elusive HISS factor is indeed an RSNO, or another nitrosylated molecule for that matter, remains to be shown [50,51]. …”