| Flavins are important natural coenzymes for a large number of redox enzymes known as flavoenzymes. The oxidation of NADH to NAD is one of many important flavoenzymes because it is a key step in respiration. Surfactants have been known to accelerate or inhibit these biological redox reactions. We used four different flavins and four different surfactants to observe the effect mixing these compounds would have on the oxidation of N-benzyldihydronicotinamide, a synthetic analog of the natural nicotinamide dihydronicotinamide adenine dinucleotide (NADH). The four surfactants used are dodecyltrimethylammonium bromide (DTAB, a cationic surfactant), sodium dodecyl sulfate (SDS, an anionic surfactant), perfluoro-1-octanesulfonicacid tetraethylammonium salt (POAT, a cation fluorinated surfactant), and [3-[[(heptadecafluorooctyl) sulfonyl]amino]propyl]trimethyl-ammonim iodide (17FOSI, an anionic fluorinated surfactant). The four flavins used are N(10)-butyl-7-trimethylflavin, N(10)-dodecylflavin-7-carboxylic acid, N(10)-butylflavin-7-carboxylic acid, and N(10)-octylflavin-7-carboxylic acid.; The kinetics study demonstrated mostly an inhibitory effect on the catalytic oxidation reactions.; The second part of the dissertation dealt with monolayers and Langmuir-Blodgett (LB) films. We used N(10)-hexadecyl-isoalloxazine-7-carboxylic acid (C16Fl) as our representative flavin and used two amino acid surfactants N-stearoyl-L-tyrosine methyl ester (STME) and N stearoyl-L-serine methyl ester (SSME) to form mixed monolayers.; The monolayer studies provided information about how close in proximity the flavin's ring and the flavin's hydrocarbons are to the liquid surface.; For the LB films, the transfer of the monolayers to the indium tin oxide (ITO) glass slides with the mixtures of the amino acids occurred with high transfer ratios, the ratio for STME being higher than the ratio for SSME. The electron transfer rates for LB films of flavin derivatives are slower than those reported for self-assembled monolayers. There was a high degree of ring stacking achieved from the slow compression on the water surface. (Abstract shortened by UMI.)... |
