Mollusk shell organic matrix: Fourier transform infrared study of the acidic macromolecules

✍ Scribed by Worms, Daniele ;Weiner, Stephen

• Publisher: John Wiley and Sons
• Year: 1986
• Tongue: English
• Weight: 742 KB
• Volume: 237
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402370104

✦ Synopsis

Ion-binding ligands and the conformations of some of the acidic matrix macromolecules present in the shells of a gastroped, a bivalve, and a cephalopod, are investigated in vitro by Fourier transform infrared spectroscopy. The complex assemblage of matrix constituents present in the EDTAsoluble fraction is first separated into two quite different classes of macromolecules by a reversed-phase chromatographic procedure. Infrared spectra indicate that the constituents of one class, which are proteins rich in aspartic acid, adopt the 0-sheet conformation upon binding calcium to the protein carboxylate groups. The second class of matrix constituents contains proteins rich in serine that appear to be associated with relatively large amounts of polysaccharide. They also bind calcium and upon doing so undergo a conformational change. 0 1986 ALAN R. LISS, INC. 'In this region CH, scissoring CH3 bending, amide I11 vibrations are observed around 1455 cm-I, 1380 cm-', and between 1325 and 1360 cm--I respectively. The four peaks are not always well resolved. S, strong intensity band; w, weak intensity hand.