Interaction of Insulin and Polymer Surface Investigated by Surface-MALDI-TOF-Mass Spectrometry

• Main Authors: Zahida Ademović, Jochen Salber, Doris Klee
• Format: Article
• Language: English
• Published: Croatian Chemical Society 2015-12-01
• Series: Croatica Chemica Acta
• Online Access: http://hrcak.srce.hr/file/221502

Synthetic materials in contact with protein containing solution adsorb a considerable amount of proteins. The adsorption behaviour of zinc-free porcine insulin on the hydrophobic poly(vinylidene fluoride) (PVDF) surfaces before and after chemical vapour deposition (CVD) modification was directly analysed by matrix-assisted laser desorption ionisation-time-of-flight-mass spectroscopy in surface mode (surface-MALDI-TOF-MS). The MALDI mass spectra of Zn-free porcine insulin dissolved in carbonate buffer pH 8.3 after adsorption onto non-modified and modified PVDF-CVD surfaces contain peaks assigned to monomer ion peak as well as peaks that are results of degradation of Zn-free porcine insulin. The degradation is caused by structural changes taking place during adsorption of insulin onto hydrophobic surfaces and by subsequent laser induced desorption and ionisation process. Surface spectra of Zn-free porcine insulin dissolved in deionised water show only monomer ion peaks of porcine insulin without degradation product detected. Structure stability of Zn-free porcine insulin upon adsorption is influenced by hydrophobic interaction between insulin and the surface.