title: The measurement of conformational stability of proteins adsorbed on siloxanes.
abstract: The paper investigates the conformational stability of bovine serum albumin (BSA) and fibrinogen during 24-h incubation in turn with a linear silicone polymer (polydimethylsiloxane (PDMS)), with linear silicone oligomers (hexamethyldisiloxane and octamethyltrisiloxane) and with cyclic silicone oligomers (octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5)). Ten-fold and 100-fold excesses of siloxanes with respect to the proteins were used. Using fluorescence spectroscopy of tryptophan located in the domain of proteins and fluorescence of 8-anilino-1-naphthalenesulfonic acid (1,8-ANS), which interacts with hydrophobic domains of proteins, changes in the tertiary structure of the protein were recorded. The results demonstrated that BSA does not change its native form during 24-h incubation with siloxanes. In contrast, the tertiary structure of fibrinogen was found to be altered by both short-chain linear siloxanes: (hexamethyldisiloxane and octamethyltrisiloxane) and long-chain PDMS. The changes can be observed only at a 100-fold excess of siloxanes with respect to the protein. No conformational changes in fibrinogen exposed to cyclic siloxanes were observed.
authors.affiliation: Division of Physical Chemistry with Instrumental Analysis Laboratory, Medical Academy of Gdańsk, Hallera 107, 80-416 Gdańsk, Poland. magdap@amg.pl
authors.forename: Magdalena
authors.initials: M
authors.lastname: Prokopowicz
authors.forename: Bogdan
authors.initials: B
authors.lastname: Banecki
authors.forename: Jerzy
authors.initials: J
authors.lastname: Lukasiak
authors.forename: Andrzej
authors.initials: A
authors.lastname: Przyjazny
mesh_terms: D000327:Adsorption; D000817:Anilino Naphthalenesulfonates; D000818:Animals; D002417:Cattle; D004129:Dimethylpolysiloxanes; D004655:Emulsions; D005340:Fibrinogen / Q000737:chemistry*; D005456:Fluorescent Dyes; D009757:Nylons; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D012833:Siloxanes; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D014783:Viscosity
chemical_list: D000817:Anilino Naphthalenesulfonates; D004129:Dimethylpolysiloxanes; D004655:Emulsions; D005456:Fluorescent Dyes; D009757:Nylons; D011506:Proteins; D012833:Siloxanes; C085707:poly(dimethylsiloxane)-polyamide copolymer; D012710:Serum Albumin, Bovine; C027132:1-anilino-8-naphthalenesulfonate; D005340:Fibrinogen