engleski

Application of the newly synthesized Man9 glycoprobe to analyze activity of mannan binding lectin in human sera

Aiming to improve tools for the analysis of lectins, we have recently developed a new class of complex neoglycoconjugates named Glycoprobes (Glycobiology 10:357, 2000). Glycoprobes consists of a oligosaccharide ligand, photoreactive crosslinker and a digoxin tag, and enable direct analysis of lectin activity in complex biological samples. Mannan-binding lectin (MBL) is a C-type lectin with a typical soluble collectin structure. It functions as a pattern recognition molecule that binds repeating sugar arrays on many microbial surfaces. Its ability to activate complement response makes it an important player in the first line of defense, as well as in some pathological processes. To be able to analyze MBL activity in human serum we synthesized a specific glycoprobe containing Mannose9-N-Acetylganactosamine2 (Man9) glycan as a ligand. Using Man9-glycoprobe we assayed MBL activity in 30 sera of patients with rheumatoid arthritis and 25 sera of matching healthy controls. It is important to note that this was the first example where activity, and not the simple presence of MBL protein was assayed. Very large biological variability of MBL activity was found to exist in both studied groups, while there appeared to be no significant difference between the groups. This result does not support the hypothesis that binding of MBL to degalactosylated olgosaccharides on IgG contributes to the pathology of rheumatoid arthritis.

Man9 glycoprobe; activity of lectins; mannan binding lectin

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