You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Characterization Studies on the Cadmium-Binding Proteins from Two Species of New Zealand Oysters
Monica Nordberg, Iris Nuottaniemi, M. George Cherian, Gunnar F. Nordberg, Tord Kjellström and Justine S. Garvey
Environmental Health Perspectives
Vol. 65 (Mar., 1986), pp. 57-62
Published by: The National Institute of Environmental Health Sciences
Stable URL: http://www.jstor.org/stable/3430163
Page Count: 6
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
Two different types of New Zealand oysters-Ostrea lutaria (OL) and Crassostrea glomerata (CG)-contained different concentrations of zinc, copper, and cadmium. OL oysters had 5.3 μg Cd/g, 3.4 μg Cu/g, 100 μg Zn/g; CG oysters had 1.4 μg Cd/g and 936 μg Zn/g. Both kinds of oysters were shown by gel filtration (G-75) to contain cadmium and zinc in fractions corresponding to a high molecular weight protein (corresponding to the size of albumin or larger) which was heat labile. OL oysters contained cadmium in fractions corresponding to a molecular weight of approximately 6500. The cadmium-binding protein in these fractions was heat-stable. This protein contained no detectable amounts of zinc and was not present in the CG oysters. Further purification by gel filtration (G-50) was performed to obtain a purer protein fraction. Isoelectric focusing of the protein obtained by G-50 filtration showed one main fraction of protein with a pI ∼ 5.9 at ∼ 13°C. CG oysters contained cadmium and zinc in a polypeptide with low molecular weight (MW 1000). The cadmium-binding oyster proteins are minimally reactive in a competitive binding radioimmunoassay in comparison to the reactivity of a typical vertebrate metallothionein; the proteins may be metallothioneins, but, if so, they do not exhibit the principal determinants characteristic of vertebrate metallothioneins.
Environmental Health Perspectives © 1986 The National Institute of Environmental Health Sciences