Ichthyocoll

Most of the quantitative discrepancies and contradictions arising from these studies were resolved by the work of Boedtker and Doty (1956) who carried out a very careful study of soluble ichthyocol collagen in pH 3.7... 

Correlation of the kinetics of proteolysis of ichthyocol by the enzyme collagenase with changes in various physical parameters, indicate that the native molecule must be multistranded (von Hippel et al., 1960). 

Fig. 19. Comparison of the fractional decrease in specific viscosity and specific rotation as a function of time after adding collagenase to soluble ichthyocol collagen at 14.3°C. (From von Hippel et al., 1960. Reproduced with kind permission of the American Chemical Society.)...

In Fig. 21, the logarithms of the apparent first-order rate constants obtained from a series of pH-stat runs on ichthyocol collagen at various temperatures are plotted against the reciprocal of the absolute temperature as an Arrhenius plot. Clearly the data fall onto three straight lines those numbered (2) and (3) for the two reactions at temperatures below Td, line (1) for the single reaction at temperatures above To. The apparent enthalpy (AH ), free energy (AF ), and entropy (AS ) of activation, together with the fraction of the susceptible bonds split in each reaction, arc compiled in Table XI. 

Fig. 20a. Fraction of the susceptible bonds of soluble ichthyocol collagen cleaved by collagenase, as a function of time at 19.5°C. ( ), Experimental points ( ), fast reaction (calculated by subtracting the extrapolated slow reaction from the experimental data. (From von Hippel el al., 1960.)...

Thermodynamic Data, Collagenase on Ichthyocol Collagen and Gelalin"... 

Fig. 21. Arrhenius plots for the proteolysis of ichthyocol collagen and gelatin by collagenase. pH-stat data (1) gelatin above To (2) collagen below To, fast reaction (3) collagen below To, slow reaction. (Prom von Hippel ei al., 1960.)...

The molecular weights of the two components of ichthyocol and calfskin gelatin have been estimated from their respective sedimentation coefiicients... 

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