Answers are grounded in this paper and cite their sources.
Earthworm cuticle is composed of collagenous material which can be extracted nearly completely with NaCl or dilute acetic acid solutions. The salt- and acid-extracted collagens differ little in their chemical composition, and produce galactobiitol and galactotriitol in the same ratio upon alkaline borohydride treatment. These oligosaccharide chains appear to be linked directly to threonine and serine residues.
No takes yet. Share an insight, caveat, or question.
Y.C. Lee (1970) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: