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.
Myosin head actin together with the products of ATP hydrolysis, performs a power stroke associated with release of hydrolysis products, and detaches from actin upon binding with new ATP. The detached myosin head then hydrolyses ATP, and performs a recovery stroke to restore its initial position. The strokes have been suggested to result from rotation of the lever arm domain around the converter domain, while the catalytic domain remains rigid. Myosin head Muscle contraction is caused by the sliding action of thick filaments over thin filaments of the myofibril. Myosin is a major component of thick filaments and most myosin molecules are