Reactive disulfide bonds in immunoglobulin G. A unique feature in serum proteins of different species.
A reactive disulfide bond (SS)* was detected and characterized in IgG of humans, rats and mice by virtue of disulfide interchange with dithionitrobenzoate. (SS)* was found exclusively in human IgG1 and rat IgG2b. In human IgG1 (SS)* was identified as the upper one of the two interheavy bridges in the hinge, where it appears to take part in complement activation. The biological significance of (SS)* in IgG was underlined by the fact that no other serum proteins were found to exhibit a similar reactivity.
Institute of Biochemistry, University of Graz, Austria.
E
E
Schauenstein
K
K
Schauenstein
F
F
Dachs
M
M
Reiter
A
A
Leitsberger
M
M
Weblacher
K
K
Maninger
H
H
Horejsi
W
W
Steinschifter
C
C
Hirschmann
P
P
Felsner
D000818:Animals; D001345:Autoradiography; D001798:Blood Proteins / Q000737:chemistry / Q000378:metabolism; D002250:Carbon Radioisotopes; D004220:Disulfides / Q000737:chemistry* / Q000378:metabolism; D004228:Dithionitrobenzoic Acid / Q000737:chemistry; D005609:Free Radicals; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D051379:Mice; D051381:Rats; D017207:Rats, Sprague-Dawley; D013438:Sulfhydryl Compounds
D001798:Blood Proteins; D002250:Carbon Radioisotopes; D004220:Disulfides; D005609:Free Radicals; D007074:Immunoglobulin G; D013438:Sulfhydryl Compounds; D004228:Dithionitrobenzoic Acid