European Journal of Mass Spectrometry - Abstract of In vitro nitrosation of insulin A- and B-chains

Celina Santos,^a Ricardo A. Afonso,^c,d Maria Pedro Guarino,^c,e Rita S. Patarrão,^c,d Ana Fernandes,^c João Paulo Noronha,^a M. Paula Macedo^c,f and Jorge Caldeira^*,a,b
^aREQUIMTE, Departamento de Química, FCT-UNL, 2829-516 Caparica, Portugal. E-mail: fjc@dq.fct.unl.pt
^b Instituto Superior de Ciências da Saúde Egas Moniz, 2829-516 Caparica, Portugal
^cDepartamento de Fisiologia, FCM-UNL Campo dos Mártires da Pátria, n. 130, 1169-056 Lisboa, Portugal
^dDepartamento de Bioquímica, FCM-UNL Campo dos Mártires da Pátria, n. 130, 1169-056 Lisboa, Portugal
^eDepartamento de Fisiopatologia, FCM-UNL Campo dos Mártires da Pátria, n. 130, 1169-056 Lisboa, Portugal
^fAssociação Protectora dos Diabéticos de Portugal (APDP), Rua do Salitre, 118, 1250-203 Lisboa, Portugal

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.