MBPdimeroftrimersClassical pathwayC-typeCCDCRDsAntibodiesProteasedomainLectinpathwayMASPMBP-MASPC1g-C1r-C1sSushi-CUBdimerEGFdomainsIC4-C2Gly-37→GluNC3C3a+C3bGly-34→AspCollagentailsC5-C9OpsonizationCell lysis(phagocytosis)
MBPdimeroftrimersC-typeCRDs1.Fixed distance between CRDProtease2.Orientation: face the samedomaindirectionMASPSuitable to the role of MBP indimerinteracting with surfaces ofmicroorganismsGly-37→GluNGly-34→>AspAssociationwithMBP-associatedCollagenserineprotease(MASP)tailsTrimer stabilized by two helical regionsAneckof coiledcoil ofa-helicesAn extended tail forms a collagen-like helix
Trimer stabilized by two helical regions A neck of coiled coil of α-helices An extended tail forms a collagen-like helix Association with MBP-associated serine protease (MASP) 1.Fixed distance between CRD 2.Orientation: face the same direction Suitable to the role of MBP in interacting with surfaces of microorganisms
3PathogenrecognitionbyMBPresultsfrom both monosaccharide-bindingspecificity and oligomer geometry
3 Pathogen recognition by MBP results from both monosaccharide-binding specificity and oligomer geometry
.Theabilityof MBPto distinguishbetween selfand non-self is based on the differentcompositions and structures of mammalianglycoproteins and glycolipids compared withthose on the surfaces of most microorganisms· Glycans on bacteria, yeast, and fungi differwidely, but many share a few key characteristics.Theyusuallyservestructuralroles· Repetitive structures with terminal Glc, GlcNAcand Man
• The'ability'of'MBP'to'dis4nguish'between'self' and'non;self'is'based'on'the'different' composi4ons'and'structures'of'mammalian' glycoproteins'and'glycolipids'compared'with' those'on'the'surfaces'of'most'microorganisms.' • Glycans'on'bacteria,'yeast,'and'fungi'differ' widely,'but'many'share'a'few'key'characteris4cs' • They'usually'serve'structural'roles' • Repe44ve'structures'with'terminal'Glc,'GlcNAc and'Man
· Recognition by MBP takes advantages of bothofthesefeatures. MBP shows equal affinity for Glc, Man andGlcNAc in terminal positions
• Recogni4on'by'MBP'takes'advantages'of'both' of'these'features' • MBP'shows'equal'affinity'for'Glc,'Man'and' GlcNAc'in'terminal'posi4ons