Ichthyocol solubility

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... 

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.)...

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.)...

Fig. 23. Specific rotation of ichthyocol collagen and gelatin at 313 wn as a function of temperature. Collagen concentration = 1.14 mg/ml, gelatin concentration = 1.67 mg/ml. T, gelatin, after 24 hr at 3°C A, gelatin after 6 days at 3°C O, gelatin after 28 days at 3°C O, native soluble collagen. (From Harrington and von Hippel, 1961.)...

An indication that hexoses are involved in the intramolecular cross-linking is found in the data of Hermann et al. (1959) on the action of periodic, acid on acid-soluble collagen from calfskin (Table X). In this sample approximately 1 mole of HIO4 is used per hexose unit present. If, however, the hexose was linked only in the C-1 position as found in ichthyocol (Blumenfeld et al., 1963b), then 2 moles of HIO4 would be required. This supports the hypothesis that transesterification is involved in the foimation of intramolecular cross-links. Such transesterification will... 

Collagens from various sources can be dispersed in differing degrees. Leplat (136) examined different animal tendons, emplo3dng formic, propionic, citric and even hydrochloric acids for their partial solution. Faur Fremiet and Baudouy (71) found ichthyocol completely soluble in 0.0004 N formic acid and formamide, the latter also dispersing mammalian tendons partially. Salo (184) has reported molecular shapes and sizes, similar to those of Scatchard et al. for parent gelatin, from viscosity studies of ichthyocol dispersed in warm dilute acetic acid solutions containing some salt. 

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