Abnormal glycosylation of hemopexin in arthritic rats can be blocked by bindarit.
Induction of arthritis in rats with Freund's complete adjuvant was accompanied by a distinctive alteration of concanavalin A (Con-A) reactivity in their serum proteins in which the concentrations of selected Con-A reactive proteins were significantly higher when compared to healthy rats. To assess if the observed increase in Con-A reactivity of specific serum proteins reflects an increase in carbohydrate moieties in these proteins in addition to an increase in their protein concentrations, a heme binding serum glycoprotein, hemopexin, also an acute phase reactant, was selected as a marker protein. Hemopexin was purified to apparent homogeneity from pools of serum samples derived from rats with yeast induced inflammation, a monospecific polyclonal antibody was prepared and was used for immunoblot analysis. It was noted that the concentration of hemopexin increased in rats with adjuvant induced arthritis; however, its concentration fell to normal levels after administration with a newly synthesized drug, bindarit, (2-[(1-benzyl-indazol-3-yl)methoxy]-2-methyl propionic acid, C19H20N2O3. Hemopexin was micropurified individually from healthy rats, adjuvant induced arthritic rats, and adjuvant arthritic rats treated with bindarit, cleaved with a Glu-C endopeptidase, Staphylococcus aureus protease V8, and the resultant peptide fragments resolved by SDS-PAGE and examined by silver staining, Coomassie blue staining, and lectin blots using Con-A. It was subsequently noted that hemopexin isolated from adjuvant induced arthritic rats showed a significant increase in Con-A reactivity in selected peptide fragments and that such an increase in glycosylation could be reversed to a pattern similar to healthy rats following treatment with bindarit.(ABSTRACT TRUNCATED AT 250 WORDS)
Saso
L
L
Population Council, New York, NY 10021.
Silvestrini
B
B
Zwain
I
I
Guglielmotti
A
A
Luparini
M R
MR
Cioli
V
V
Cheng
C Y
CY
D000210:Acute-Phase Reaction; D000595:Amino Acid Sequence; D000818:Animals; D001169:Arthritis, Experimental / Q000378:metabolism*; D001798:Blood Proteins / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003208:Concanavalin A / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000032:analysis; D005620:Freund's Adjuvant; D006031:Glycosylation / Q000187:drug effects; D006466:Hemopexin / Q000302:isolation & purification / Q000378:metabolism*; D015151:Immunoblotting; D007191:Indazoles / Q000494:pharmacology*; D008969:Molecular Sequence Data; D011422:Propionates / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013194:Staining and Labeling
D001798:Blood Proteins; D007191:Indazoles; D011422:Propionates; D003208:Concanavalin A; D005620:Freund's Adjuvant; D006466:Hemopexin; D010450:Endopeptidases; C079489:bindarit