skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Quantification of metallothioneins by a silver-saturation method

Abstract

The binding of Ag+ to metallothionein (MT) was investigated, and a Ag-saturation assay was developed for the measurement of MT in tissues. When samples of purified hepatic Zn-MT or Cd-MT were titrated with Ag+ followed by hemolysate-heat treatment, it was found that saturation of MT occurred at 17 to 18 g-atoms Ag+/mol protein. The rank order of potencies of metals to displace Ag+ from 110mAg-labeled Ag-MT was Ag+ greater than Cu2+ greater than Cd2+ greater than Hg2+ greater than Zn2+ at pH 8.5 in 0.5 M glycine buffer. When a Ag-saturation (Ag-hem) assay was compared with a Cd-saturation (Cd-hem) technique, excellent correspondence was obtained in the measurement of MT from various sources including purified Zn-MT (II), MT in human kidney and liver tissue samples, hepatic MT in Cd-injected adult rats, and renal MT in Hg-injected adult rats. However, in cases where significant amounts of Cu-MT were present, such as in the livers of Cu-injected rats or in the kidneys of Cd-injected rats, the Cd-hem assay consistently underestimated the MT concentrations compared to the Ag-hem method. This is attributed to the inability of Cd to displace Cu effectively from MT at pH 8.5. Thus the Cd-hem assay is not recommended formore » the measurement of metallothioneins containing a high Cu content. Under such conditions, the Ag-hem method seems superior.« less

Authors:
;
Publication Date:
Research Org.:
Univ. of Western Ontario, London
OSTI Identifier:
5615343
Resource Type:
Journal Article
Journal Name:
Toxicol. Appl. Pharmacol.; (United States)
Additional Journal Information:
Journal Volume: 3
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; METALLOTHIONEIN; QUANTITATIVE CHEMICAL ANALYSIS; CADMIUM; CHEMICAL BONDS; COPPER; LIVER; MEASURING METHODS; MERCURY; RATS; SILVER; TISSUE DISTRIBUTION; ZINC; ANIMALS; BODY; CHEMICAL ANALYSIS; DIGESTIVE SYSTEM; DISTRIBUTION; ELEMENTS; GLANDS; MAMMALS; METALLOPROTEINS; METALS; ORGANIC COMPOUNDS; ORGANS; PROTEINS; RODENTS; TRANSITION ELEMENTS; VERTEBRATES; 560301* - Chemicals Metabolism & Toxicology- Cells- (-1987)

Citation Formats

Scheuhammer, A M, and Cherian, M G. Quantification of metallothioneins by a silver-saturation method. United States: N. p., 1986. Web. doi:10.1016/0041-008X(86)90277-2.
Scheuhammer, A M, & Cherian, M G. Quantification of metallothioneins by a silver-saturation method. United States. https://doi.org/10.1016/0041-008X(86)90277-2
Scheuhammer, A M, and Cherian, M G. Sat . "Quantification of metallothioneins by a silver-saturation method". United States. https://doi.org/10.1016/0041-008X(86)90277-2.
@article{osti_5615343,
title = {Quantification of metallothioneins by a silver-saturation method},
author = {Scheuhammer, A M and Cherian, M G},
abstractNote = {The binding of Ag+ to metallothionein (MT) was investigated, and a Ag-saturation assay was developed for the measurement of MT in tissues. When samples of purified hepatic Zn-MT or Cd-MT were titrated with Ag+ followed by hemolysate-heat treatment, it was found that saturation of MT occurred at 17 to 18 g-atoms Ag+/mol protein. The rank order of potencies of metals to displace Ag+ from 110mAg-labeled Ag-MT was Ag+ greater than Cu2+ greater than Cd2+ greater than Hg2+ greater than Zn2+ at pH 8.5 in 0.5 M glycine buffer. When a Ag-saturation (Ag-hem) assay was compared with a Cd-saturation (Cd-hem) technique, excellent correspondence was obtained in the measurement of MT from various sources including purified Zn-MT (II), MT in human kidney and liver tissue samples, hepatic MT in Cd-injected adult rats, and renal MT in Hg-injected adult rats. However, in cases where significant amounts of Cu-MT were present, such as in the livers of Cu-injected rats or in the kidneys of Cd-injected rats, the Cd-hem assay consistently underestimated the MT concentrations compared to the Ag-hem method. This is attributed to the inability of Cd to displace Cu effectively from MT at pH 8.5. Thus the Cd-hem assay is not recommended for the measurement of metallothioneins containing a high Cu content. Under such conditions, the Ag-hem method seems superior.},
doi = {10.1016/0041-008X(86)90277-2},
url = {https://www.osti.gov/biblio/5615343}, journal = {Toxicol. Appl. Pharmacol.; (United States)},
number = ,
volume = 3,
place = {United States},
year = {1986},
month = {3}
}