Mannan-binding lectin Mannan-binding lectin Mannose-binding lectin (MBL), also called mannose-binding protein or mannan-binding protein (MBP), is a lectin that is instrumental in innate immunity via the lectin pathway. MBL has an oligomeric structure (400-700 kDa), built of subunits that contain three presumably identical peptide chains of about 30 kDa each. Although MBL can form several oligomeric forms, there are indications that dimers and trimers are not biologically active and at least a tetramer form is needed for activation of complement. Human MBL2 gene is located on chromosome 10q11.2-q21. Mice have two homologous genes, but in human the first of them was lost.
Lysyl oxidase the aldehyde product, allysine. Molecular oxygen and the copper ion are utilized to reoxidize the cofactor and yield another imine, producing hydrogen peroxide as a side product. Additional hydrolysis releases ammonia and the original cofactor, completing the catalytic cycle. Lysyl oxidase is an extracellular copper-dependent enzyme that catalyzes formation of aldehydes from lysine residues in collagen and elastin precursors. These aldehydes are highly reactive, and undergo spontaneous chemical reactions with other lysyl oxidase-derived aldehyde residues, or with unmodified lysine residues. This results in cross-linking collagen and elastin, which is essential for stabilization of collagen fibrils and for the integrity and