Open AccessBiotransformation of intracellular minerals by zinc ions in vivo and in vitro
Author(s) -
TAYLOR Marina G.,
GREAVES G. Neville,
SIMKISS Kenneth
Publication year - 1990
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1990.tb19291.x
Subject(s) - pyrophosphate , in vivo , zinc , chemistry , zinc phosphate , biophysics , hydrolysis , phosphate , intracellular , amorphous solid , in vitro , extracellular , mineral , biomineralization , biochemistry , crystallography , chemical engineering , biology , enzyme , organic chemistry , microbiology and biotechnology , engineering
Inorganic granules of the general type CaMgP 2 O 7 are found within cells of a wide range of species. The granules are amorphous to X‐rays and occur in membrane‐bound compartments. They accumulate a variety of cations from the body fluids of these animals. The interaction of zinc ions with pyrophosphate granules from cells of the snail Helix aspersa have been studied in vivo and in vitro by X‐ray absorption spectroscopy and X‐ray diffraction. The in vivo deposits incorporate zinc and remain amorphous although the pyrophosphate is hydrolysed to orthophosphate. In the in vitro reaction the mineral becomes crystalline but there is little change in the form of the anion. The results clearly indicate a role for the cellular system in maintaining the amorphous state and in the hydrolysis of pyrophosphate to orthophosphate. As such they provide a model system for some of the changes observed in precursors of bone mineral and in pathological changes in the calcification of cartilage.