Abstract
In order to study aspects of the stoichiometry and composition of human MBL–MASP complexes in the population, MBL–MASP complexes were bound from sera of 152 healthy individuals onto mannan-coated microtitre plates. Bound mannan-binding lectin (MBL) was measured by ELISA, and the enzyme activities of MBL-bound MASP-1 and MASP-2 were measured by an amidolytic assay and a C4 fixation assay, respectively. MASP-1 activity correlated with MBL concentration, as did MASP-2 activity (in both cases: p < 0.0001). This is expected since MASP-1 and MASP-2 are bound to the mannan via MBL. However, when MASP activities were normalised to MBL concentration (i.e. MASP-1 activity/[MBL], MASP-2 activity/[MBL]) MASP-1 activity was inversely correlated with MASP-2. This means on average that high MASP-1 correlates with low MASP-2 and vice-versa, and confirms the hypothesis that native MBL–MASP complexes on average do not have fixed MBL-(MASP-1)-(MASP-2) stoichiometry. The findings are consistent with separate populations of MBL–MASP-1 complexes and MBL–MASP-2 complexes, the concentrations of which show wide inter-individual variation.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
