RESUMEN
A 90-kDa protein-actin stable complex was purified from blood platelets by a short and efficient procedure giving at the same time actin used in polymerization assays. 90-kDa protein free of actin was prepared from the complex by 8 M ureau treatment and renaturation. By its molecular mass, immunological cross-reactivity with macrophage gelsolin and its effect on G- and F-actin the 90-kDa protein appears as the platelet gelsolin.
Asunto(s)
Plaquetas/análisis , Proteínas de Unión al Calcio/aislamiento & purificación , Actinas/sangre , Actinas/aislamiento & purificación , Proteínas de Unión al Calcio/metabolismo , Cromatografía en Gel , Electroforesis en Gel de Poliacrilamida , Gelsolina , Humanos , Cinética , Sustancias Macromoleculares , Peso Molecular , ViscosidadRESUMEN
Two forms, A and B, of octopine dehydrogenase from Pecten muximus L. straited adductor muscles were separated by ion-exchange chromatography and purified to homogeneity. Their kinetic properties were similar and, among others, the mnemonical behaviour, previously found for octopine dehydrogenase, was confirmed. Structural features, determined by polyacrylamide gel electrophoresis with and without sodium dodecylsulfate, amino acid composition, immunological tests and heat stability were compared. The only differences between the two forms are their charge and their sensibility to various chemical treatments. Assays of reciprocal conversion of the two forms by oxidation, reduction or deamidation failed. No tissue specificity and no relation to any physiological conditions could be observed. However, a constant ratio A:B = 1:4 was statistically found in crude extracts as well as in the purified enzyme. It therefore seems possible to assume that the two forms of octopine dehydrogenase pre-exist in living P. maximus, although their genetic origin has to be established.