Activating Compound | Comment | Organism | Structure |
---|---|---|---|
properdin | properdin (Factor P) binding to the erythrocyte membranes is necessary for C3b to attach and initiate alternative pathway activation | Homo sapiens | |
zymosan | it is capable of activating the classical pathway as well as the alternative pathway, when the classical pathway is blocked, mechanism, overview | Homo sapiens |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
Aurin tricarboxylic acid | blocks the alternative pathway at a downstream step from C3b attachment. It prevents formation of C3 convertase at the stage where Factor B, attached to the membrane-bound properdin-C3b-Factor B (PC3bB) complex, is cleaved by the protease action of Factor D to form the active C3 convertase enzyme PC3bBb. Activity is restored by the addition of excess Factor D to the serum. But membrane attack complex formation is still blocked by ATA at the stage of C9 addition to C5b678. It has no effect on the classical pathway activation. Binding of aurin tricarboxylic acid to the QPDTIDHDLLLLQLS site blocks the ability of aurin tricarboxylic acid to bind to Factor D protein | Homo sapiens |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
membrane | - |
Homo sapiens | 16020 | - |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | P00751 | - |
- |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
erythrocyte | - |
Homo sapiens | - |
Synonyms | Comment | Organism |
---|---|---|
C3 convertase | - |
Homo sapiens |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Homo sapiens |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.4 | - |
assay at | Homo sapiens |
General Information | Comment | Organism |
---|---|---|
physiological function | the alternative pathway is activated by zymosan in human serum after blocking the classical pathway activation with either a polyclonal antibody to C4d or with C1 inhibitor. Properdin (Factor P) binding to the erythrocyte membranes is necessary for C3b to attach and initiate alternative pathway activation, regulation, overview | Homo sapiens |