Cadmium binding to human α2-macroglobulin

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

α2-Macroglobulin (α2M) is one of the major cadmium-binding proteins of human plasma. As determined with equilibrium dialysis, α2M bound 4.6 (±0.7) mol Cd2+ per mol protein with an apparent dissociation constant of (9.6 (±5.0))·10-7M. Methylamine-modified α2M (α2M-Me) had a similar affinity for Cd2+ (Kd,app = 5.3·10-7M, but fewer binding sites. Cadmium produced a small increase in the amidolytic activity of trypsin in the presence of α2M and soybean trypsin inhibitor. Using the binding parameters determined from the equilibrium dialysis studies, the Cd2+ concentration which produced a half-maximal increase in amidolytic activity corresponded to saturation of all Cd2+-binding sites in one-half of the α2M molecules. From these results, a model is proposed in which one Cd2+-binding site is present in each of the four polypeptide chains which compose α2M.

Original languageEnglish (US)
Pages (from-to)370-374
Number of pages5
JournalBiochimica et Biophysica Acta (BBA)/Protein Structure and Molecular
Volume791
Issue number3
DOIs
StatePublished - Dec 21 1984

Fingerprint

Macroglobulins
Cadmium
Dialysis
Binding Sites
Plasma (human)
Trypsin Inhibitors
Soybeans
Application programs
Trypsin
Peptides
Molecules

Keywords

  • (Human)
  • Cd binding
  • Equilibrium binding
  • α-Macroglobulin

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology
  • Structural Biology

Cite this

Cadmium binding to human α2-macroglobulin. / Carson, Steven D.

In: Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular, Vol. 791, No. 3, 21.12.1984, p. 370-374.

Research output: Contribution to journalArticle

@article{8c9a1040fc4045748a46483a2fa7095a,
title = "Cadmium binding to human α2-macroglobulin",
abstract = "α2-Macroglobulin (α2M) is one of the major cadmium-binding proteins of human plasma. As determined with equilibrium dialysis, α2M bound 4.6 (±0.7) mol Cd2+ per mol protein with an apparent dissociation constant of (9.6 (±5.0))·10-7M. Methylamine-modified α2M (α2M-Me) had a similar affinity for Cd2+ (Kd,app = 5.3·10-7M, but fewer binding sites. Cadmium produced a small increase in the amidolytic activity of trypsin in the presence of α2M and soybean trypsin inhibitor. Using the binding parameters determined from the equilibrium dialysis studies, the Cd2+ concentration which produced a half-maximal increase in amidolytic activity corresponded to saturation of all Cd2+-binding sites in one-half of the α2M molecules. From these results, a model is proposed in which one Cd2+-binding site is present in each of the four polypeptide chains which compose α2M.",
keywords = "(Human), Cd binding, Equilibrium binding, α-Macroglobulin",
author = "Carson, {Steven D.}",
year = "1984",
month = "12",
day = "21",
doi = "10.1016/0167-4838(84)90349-2",
language = "English (US)",
volume = "791",
pages = "370--374",
journal = "Biochimica et Biophysica Acta - Proteins and Proteomics",
issn = "1570-9639",
publisher = "Elsevier",
number = "3",

}

TY - JOUR

T1 - Cadmium binding to human α2-macroglobulin

AU - Carson, Steven D.

PY - 1984/12/21

Y1 - 1984/12/21

N2 - α2-Macroglobulin (α2M) is one of the major cadmium-binding proteins of human plasma. As determined with equilibrium dialysis, α2M bound 4.6 (±0.7) mol Cd2+ per mol protein with an apparent dissociation constant of (9.6 (±5.0))·10-7M. Methylamine-modified α2M (α2M-Me) had a similar affinity for Cd2+ (Kd,app = 5.3·10-7M, but fewer binding sites. Cadmium produced a small increase in the amidolytic activity of trypsin in the presence of α2M and soybean trypsin inhibitor. Using the binding parameters determined from the equilibrium dialysis studies, the Cd2+ concentration which produced a half-maximal increase in amidolytic activity corresponded to saturation of all Cd2+-binding sites in one-half of the α2M molecules. From these results, a model is proposed in which one Cd2+-binding site is present in each of the four polypeptide chains which compose α2M.

AB - α2-Macroglobulin (α2M) is one of the major cadmium-binding proteins of human plasma. As determined with equilibrium dialysis, α2M bound 4.6 (±0.7) mol Cd2+ per mol protein with an apparent dissociation constant of (9.6 (±5.0))·10-7M. Methylamine-modified α2M (α2M-Me) had a similar affinity for Cd2+ (Kd,app = 5.3·10-7M, but fewer binding sites. Cadmium produced a small increase in the amidolytic activity of trypsin in the presence of α2M and soybean trypsin inhibitor. Using the binding parameters determined from the equilibrium dialysis studies, the Cd2+ concentration which produced a half-maximal increase in amidolytic activity corresponded to saturation of all Cd2+-binding sites in one-half of the α2M molecules. From these results, a model is proposed in which one Cd2+-binding site is present in each of the four polypeptide chains which compose α2M.

KW - (Human)

KW - Cd binding

KW - Equilibrium binding

KW - α-Macroglobulin

UR - http://www.scopus.com/inward/record.url?scp=0021673311&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0021673311&partnerID=8YFLogxK

U2 - 10.1016/0167-4838(84)90349-2

DO - 10.1016/0167-4838(84)90349-2

M3 - Article

C2 - 6083804

AN - SCOPUS:0021673311

VL - 791

SP - 370

EP - 374

JO - Biochimica et Biophysica Acta - Proteins and Proteomics

JF - Biochimica et Biophysica Acta - Proteins and Proteomics

SN - 1570-9639

IS - 3

ER -