Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.7 (plasmin)
 9,023 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gamma-globulins for intravenous application (IgG-IV), processed by various methods, were tested for their ability to interact with human monocyte Fc receptors by determining the dose required to inhibit monocyte Fc receptor-mediated rosette formation and phagocytosis by half (ID50). Since dimeric and oligomeric IgG were found to be 2-3 times and 5-15 times more potent, respectively, than monomeric IgG, the varying proportions of polymeric IgG in intact IgG-IV were corrected for by calculation. The results of the rosette formation and phagocytosis tests were closely correlated, and insignificant differences between preparations processed by the same procedure were noted, while considerable differences were found between different procedures. The decreasing order of inhibitory activity was DEAE-Sephadex-treated IgG, acid-treated IgG, plasmin-digested IgG, polyethylene glycol(PEG)-precipitated IgG, IgG subjected to reduction/alkylation, IgG that underwent sulfitolysis, IgG treated with beta-propiolactone, and finally pepsin-treated IgG. Thus, while mild procedures preserve the capacity of IgG to interact with monocyte Fc receptors, chemical modification severely interferes with this important effector function.
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PMID:Effect of various treatments of gamma-globulin (IgG) for achieving intravenous tolerance on the capacity to interact with human monocyte Fc receptors. A comparative study. 373 22

Thermally modified human C-reactive protein (H-CRP) and IgG (AHGG) each activate isolated human platelets to reactions of aggregation and secretion. As these molecules exhibit many functional similarities, we questioned whether they might also share a receptor on the platelet membrane. Neither plasmin nor phospholipase C altered the platelet response to H-CRP or AHGG, although these reagents enhanced the platelet expression to acid soluble collagen (ASC). Conversely, chymotrypsin treatment of platelets resulted in an elevated response to each H-CRP and AHGG, but not to ASC. These data suggest that the H-CRP and AHGG platelet receptors share characteristics which contrast with those of the receptor for collagen. However, monomeric IgG, which can bind with the platelet and inhibit the response to AHGG, exerted no effect on the platelet response to H-CRP. Further, a functional receptor for thermally modified human or rabbit CRP was detected on rabbit platelets in the absence of a demonstrable Fc receptor for aggregated IgG. These data indicate that the platelet receptors for the modified forms of CRP and IgG are distinct.
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PMID:Comparison of the enzymatic sensitivities of the platelet receptor for human C-reactive protein and its functional relationship to the platelet IgG Fc receptor. 717 7