MBL/MASP-2, Human, ELISA kit

The mannan-binding lectin (MBL) pathway of complement activation has been established as the third pathway of complement activation. MBL is a carbohydrate-binding serum protein, which circulates in complex with serine proteases known as mannan-binding lectin associated serine proteases (MASPs). When bound to micro-organisms, the MBL complex activates the complement components C4 and C2, thereby generating the C3 convertase and leading to opsonisation by the deposition of C4b and C3b fragments. MBL is able to activate the complement activation pathway independent of the classical and alternative pathways and plays an important role in innate immunity. In this assay any influence of the classical pathway has been eliminated by using a special MBL-binding buffer, which inhibits the binding of C1q to immune complexes and disrupt the C1 complex, while leaving the carbohydrate binding activity of MBL and the integrity of the MBL complex intact.

Normal human plasma contains a MBL concentration ranging from 3.3 to 1650 U/ml. Up to 12 % of healthy Caucasian blood donors have MBL levels below 33 U/ml. The MBL level correlates with the amount of C4b-depositing capacity. However, the C4b deposition capacity can vary threefold between individuals with similar MBL concentrations.

The Hycult Biotech human functional MBL/MASP-2 assay is useful in evaluating the importance of the MBL pathway in relation to clinical manifestations. Several investigations have reported that low levels of MBL correlate with susceptibility to various infections and diseases.