Amino acids of the organic matrix of neogastropod shells

Abstract

1. 1. Analyses of the organic matrix of the shell of the neogastropods Littorina irrorata, Polinices duplicatus, Thais floridana, Pila virens, Campeloma decisum and Nassarius obsoletus have shown differences in amino acid content between the soluble and insoluble fractions of each species as well as interspecific differences in both fractions. 2. 2. Glycine, glutamic and aspartic acids, serine and alanine were present in highest concentration in both soluble and insoluble fractions. 3. 3. The soluble fraction of each species had a higher aspartic and glutamic acid content than the insoluble fraction. 4. 4. Glycine, phenylalanine and tyrosine were consistently higher in the insoluble fraction than in the soluble fraction. 5. 5. The insoluble matrix of the shell of Nassarius differed from that of the other five species in containing unusually high or low concentrations of several of the amino acids. 6. 6. The soluble and insoluble fractions of molluscan shell matrix are thought to have different functions in shell formation.