Disease relevance of A2M

• Normal horse and guinea pig sera contain the glycoprotein inhibitor alpha 2-macroglobulin, which inhibits the infectivity and hemagglutinating activity of influenza A viruses of the H2 and H3 subtypes [1].
• The presence of alpha 1-, alpha 2-macroglobulin-bound elastase-like enzymatic activity in the peritoneal exudates from pigs with pancreatitis, however, indicates that the proteinase is to some extent released as the active enzyme [2].

High impact information on A2M

• Mechanism-based fragmentation of coenzyme A transferase. Comparison of alpha 2-macroglobulin and coenzyme A transferase thiol ester reactions [3].
• In the light of these results it is concluded that the proteinase binding sites are localized on the alpha 2-macroglobulin surface and that the two subunits of this protein are either not identical or not symmetrically arranged [4].
• Presence of follipsin complexed with alpha 2-macroglobulin in porcine ovarian follicular fluid [5].
• The endocytosis of both conjugate was inhibited by alpha 2-macroglobulin-trypsin complex, indicating that the conjugates were endocytosed by an alpha 2-macroglobulin receptor system [6].
• In surviving pigs (n = 14), biochemical signs of protease activation evolved in plasma, including formation of trypsin-protease inhibitor complexes, a decline in C3 and kininogen levels, and a decline in functionally active alpha 2-macroglobulin, functionally active antithrombin III, and plasma kallikrein inhibitory activity [7].

Anatomical context of A2M

• Kininogen, alpha-2-macroglobulin and alpha-1-proteinase inhibitor were measured in plasma and in peritoneal fluid [8].

Associations of A2M with chemical compounds

• To exclude alpha 2-MG-trapped thrombin activity, the extract treated with 0.2 M methylamine was incubated for two hours and the residual activity was excluded from the initial thrombin activity [9].
• The effects of serum and of the protease inhibitors alpha-2 macroglobulin, pepstatin, and leupeptin on protein release were examined [10].
• Except for a slight attenuating effect on the antithrombin III (ketanserin and dipyridamole) and alpha 2-macroglobulin (ketanserin) decreases, there were no significant effects of the drugs [11].

Analytical, diagnostic and therapeutic context of A2M

• The interaction between alpha 2-macroglobulin-bound trypsin and the inhibitor was demonstrated by affinity chromatography and trypsin inhibition [4].
• The protein was immunoprecipitated with antihuman alpha 2-macroglobulin antibody and was visualized in Western blot analysis using the same antibody [5].
• Hedgehog beta-macroglobulin (Mr 700,000) gave subunits of 34,000 and 39,000 after SDS-PAGE and showed cross-reactivity with swine alpha 2-macroglobulin slow [12].

References