Cross Soluble collagen

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... 

In a previous study, fibers were made from acid-soluble collagen coagulated in ammonium hydroxide solutions and cross-linked by glutaraldehyde. The work is now extended to collagen modified by the addition of small amounts of methyl cellulose. Such fibers might be suitable as absorable sutures if the physical properties can be enhanced to a level competitive with silk and catgut 5. ... 

Skeletal tissue from copper-deficient animals is characterized by a lack of bone deposition in the cartilage matrix, and the bones from these animals contain more soluble collagen than bones from control animals. The structural integrity of collagen, like elastin, depends upon cross-linking between collagen precursors. 

Collagen and gelatin are of commercial importance. As insoluble collagen, this material may be cross-linked further by tanning and thus converted to leather. The soluble gelatins are used in the manufacture of foodstuffs, film emulsions, and glue. 

Certain solutions, such as dilute alkali buffers, salt solutions, and acid buffers, are each able to extract a small proportion of collagen from collagenous material. These solutions contain collagen as the individual triple helices. Such soluble (tollagens can have no covalent intermolecular cross-links. This has been brought out in Table I taken from a review on collagen by Honnann (1960b). 

It is clear that these relatively simple organic molecules can prevent the intermolecular cross-linking of collagen. The increased solubility in neutral salt solution as well as in acid buffers indicates that intramolecular cross-linking may also be prevented. This has been confirmed by studies of the a- and /3-components of lathyritic collagen. 

Veis and Schlueter (1963) have studied the solubility and swelling properties of dentine collagen after decalcification by ethylenediamine-tetraacetic acid (EDTA). The dentine colleen behaved as if it were more extensively cross-linked than corium collagen. Having noted that the decalcified dentine collagen still contained some phosphate that was not in combination with calcium and could not be removed by EDTA,... 

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