Alkyl glycoside detergents: a simpler synthesis and their effects on kinetic and physical properties of cytochrome c oxidase.

摘要: Octyl glucoside is an effective, nonionic, solubilizing agent for membrane proteins with the advantage of ease removal by dialysis. In order to study detergent-sensitive activity cytochrome c oxidase, we chose this detergent because its simple structure and possibility synthesizing analogues test structural dependence specificity. A procedure was therefore developed that facilitates large-scale preparation octyl related alkyl glycosides, improving on previous methods eliminating crystallization steps employing a one-step purification final product Dowex 1. This new particularly important achieving level purity required obtain disaccharide, longer chain detergents in soluble form. Of glycosides prepared (octyl beta-D-glucopyranoside, beta-D-lactopyranoside, dodecyl beta-D-cellobiopyranoside, beta-D-maltopyranoside), lauryl (dodecyl) maltoside found be most successful as activator purified beef Neurospora giving two- tenfold higher activities than other commercially available detergents, Tween-20 Triton X-100. Kinetic studies using two different steady-state assay systems indicate changes are not result altered binding substrate but rather reflect effect state association enzyme (as monomer, dimer, or polymer) well intrinsic activity. By gel filtration procedures, were exist monodisperse populations micelles 50 000 8000 daltons, respectively. The small uniform chemically well-defined structures make them superior nonionic general oxidase particular, since closely approaches physiological state.