Effect of water-soluble matrix fraction extracted from the nacre of Pinctada maxima on the alkaline phosphatase activity of cultured fibroblasts

A new approach to the isolation of the water-soluble factors from nacre wit hout any demineralization is described and examined their effect on fibrobl ast cells in culture. The soluble matrix in pure water from the nacre of Pi nctada maxima was analysed by size-exclusion HPLC. Four fractions (SE1-SE4) of the water-soluble matrix (WSM) were further analysed by anion-exchange HPLC. The amino acid composition of the WSM showed that it is mainly compos ed of glycine and alanine. SE1 and SE4 had different amino acid composition s from the whole WSM. The WSM and SE4 tested on a culture of human foetus l ung tissue fibroblasts increased the alkaline phosphatase (ALP) activity. S E1 caused a decrease in ALP activity. Our results support the hypothesis th at WSM promotes the differentiation of cells in vitro. (C) 2000 Wiley-Liss, Inc.