Kristallisierte Leucinaminopeptidase aus Rinderaugenlinsen. Physikalische Konstanten, II. Hydratationsgrad und Gestaltsbestimmung mit hydrodynamischen Methoden

Abstract

The viscosity increment (v[image] = 5.08) were determined for leucine aminopeptidase from bovine lens. For the maximal degree of hydration, wmax was 0.257 g. water/g. protein. From these values and the friction ratio, it is possible to calculate the limits of probability for the ratio of the axes a/b, assuming a compact rotational elipsoid. An prolated form gives the values 3.0[less than or equal to] a/b [less than or equal to]4.0, and an oblated form gives 0.23 [less than or equal to] a/b [less than or equal to] 0.31. The effect of anomalies of shape on the axes ratio measured by hydrodynamic methods, and a correction of the axes ratio for zero degree of hydration (w = 0 g. water/g. protein) are discussed. The partial specific volumes determined earlier by pyknometric methods are confirmed by the partial specific volumes of the amino acid residues, which are calculated from the amino acid composition.