Human alpha2-macroglobulin (a2M) purified from human plasma.
a2Macroglobulin (a2M) is a large proteinase inhibitor molecule of 718kD, consisting of 4 identical subunits of 185kD each. Produced in hepatocytes and macrophages, plasma concentrations of a2M are typically 2uM in adults, and as high as 6uM in childhood. a2M has the ability to inhibit most enzymes from the serine, metallo, cysteine and aspartate subclasses. It is not a member of the SERPIN family of inhibitors. It belongs to a class of proteins that include pregnancy zone protein (PZP) and the complement proteins C3, C4 and C5. These proteins contain regions of conserved sequence as well as one or more internal b-cysteinyl-_-glutamyl thiolester bonds, which in the case of a2M are susceptible to cleavage by enzymes or by nucleophilic compounds such as methylamine or ammonium ions. Although the precise nature of the interactions is as yet unknown, it is generally thought that cleavage of a bait region within the a2M molecule by an enzyme leads to a conformational change, which then traps and/or covalently binds the enzyme (1,2). The active site of the trapped enzyme is usually still intact and able to cleave small substrates, but is inaccessible to larger natural substrates. The conformational change induced also exposes receptor-binding regions within the molecule, which may be important in the clearance of a2M-enzyme complexes from the circulation. It is thought that the main role of a2M in vivo is that of a ''backup inhibitor and scavenger of proteinases in blood and in tissues (3,4). But it has also been reported to participate in other physiological processes, including regulation of immune function (1,2). Applications: Suitable for in ELISA and IEP. Other applications have not been tested. Recommended Dilutions: Optimal dilutions to be determined by the researcher. Rz ratio (Reinheitszahl, A403/A280): 0.29 (determined spectrophotometrically). Storage and Stability: Store product at 4C if to be used immediately within two weeks. For long-term storage, aliquot to avoid repeated freezing and thawing and store at -20C. Aliquots are stable at -20C for 12 months after receipt. Dilute required amount only prior to immediate use. Further dilutions can be made in assay buffer. Note: Sodium azide is a potent inhibitor of peroxidase and should not be added to HRP conjugates. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
Reinheit:
Purified by affinity chromatography.
Formulierung:
Supplied as a liquid in a buffered stabilizer solution, 50% glycerol. No preservative added. Labeled with horseradish peroxidase (HRP).
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