title: Electrochemistry of riboflavin-binding protein and its interaction with riboflavin.
abstract: Riboflavin-binding protein (RBP, a carrier of riboflavin) plays an essential role in embryo development. Electrochemical studies of the riboflavin-RBP interactions have been so far limited to changes in polarographic and voltammetric responses of riboflavin because of lack of methods capable to detect electrochemical changes in the RBP responses. Here we used constant current chronopotentiometric stripping analysis (CPSA) with the hanging mercury drop electrode (HMDE) and square wave voltammetry (SWV) with carbon paste electrode (CPE) to investigate RBP. We found that CPSA of RBP produces electrocatalytic peak H, capable to discriminate between apoprotein and holoprotein forms of RBP. This peak is suitable for studies of RBP-riboflavin interaction at nanomolar concentrations. We observed no sign of a release of riboflavin from holoprotein adsorbed at the HMDE surface. SWV at CPE required higher concentrations of RBP and displayed almost identical oxidation peaks of apoprotein and holoprotein.
authors.affiliation: Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, 612 65 Brno, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Bartosík
authors.forename: Veronika
authors.initials: V
authors.lastname: Ostatná
authors.forename: Emil
authors.initials: E
authors.lastname: Palecek
mesh_terms: D000327:Adsorption; D000818:Animals; D001059:Apoproteins / Q000737:chemistry / Q000378:metabolism; D002244:Carbon / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000378:metabolism; D008628:Mercury / Q000737:chemistry; D011199:Potentiometry; D011485:Protein Binding; D012256:Riboflavin / Q000737:chemistry* / Q000378:metabolism; D013499:Surface Properties
chemical_list: D001059:Apoproteins; D026901:Membrane Transport Proteins; C019079:riboflavin-binding protein; D002244:Carbon; D008628:Mercury; D012256:Riboflavin