|Molecular mass||725.000 Da|
|Half-Life||2 - 3 days|
|Serum Concentration||11 days - 18 years |
19 years - 25 years
26 years - 61 years
|2.7 - 5.4 g/l |
1.8 - 16 U/ml
1.4 - 4.1 g/l
1.4 -12 U/ml
1.4 - 2.8 g/l
1.4 - 4.8 U/ml
|Normal range||Activity||0.7 - 1.50 U/ml|
As a very unspecific inhibitor, α2-macroglobulin inhibits proteases of all classes, including a variety of coagulation enzymes, such as thrombin, plasmin and kallikrein. The inhibitory activity is achieved by a so-called ‚bait region’ in the α2-macroglobulin molecule that is cleaved by the proteases. This results in a conformational change that captures the proteases in a type of cage. As α2-macroglobulin is the most important inhibitor of coagulation in new-borns, the plasma level is relatively high compared to adults.
Reduced plasma concentrations have been observed during fibrinolytic therapy and in hyperfibrinolysis. Increased concentrations are observed during pregnancy, in women taking oral contraceptives, in the nephrotic syndrome, in diabetes mellitus and as a consequence of liver disease. Increased α2-macroglobulin concentrations in adults are of no clinical significance.
Control of plasma concentration in new-borns and small children, as α2-macroglobulin is the most important inhibitor of coagulation at this age.
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