Catechol redox maintenance in mussel adhesion.

Catechol-functionalized proteins in mussel holdfasts are essential for underwater adhesion and cohesion and have inspired countless synthetic polymeric materials and devices. However, as catechols are prone to oxidation, long-term performance and stability of these inventions awaits effective antioxidation strategies. In mussels, catechol-mediated interactions are stabilized by 'built-in' homeostatic redox reservoirs that restore catechols oxidized to quinones.

The structure of chagasin in complex with a cysteine protease clarifies the binding mode and evolution of an inhibitor family.

Protein inhibitors of proteolytic enzymes regulate proteolysis and prevent the pathological effects of excess endogenous or exogenous proteases. Cysteine proteases are a large family of enzymes found throughout the plant and animal kingdoms. Disturbance of the equilibrium between cysteine proteases and natural inhibitors is a key event in the pathogenesis of cancer, rheumatoid arthritis, osteoporosis, and emphysema.

Structural basis for unique mechanisms of folding and hemoglobin binding by a malarial protease.

Falcipain-2 (FP2), the major cysteine protease of the human malaria parasite Plasmodium falciparum, is a hemoglobinase and promising drug target. Here we report the crystal structure of FP2 in complex with a protease inhibitor, cystatin. The FP2 structure reveals two previously undescribed cysteine protease structural motifs, designated FP2(nose) and FP2(arm), in addition to details of the active site that will help focus inhibitor design.

The Plasmodium falciparum cysteine protease falcipain-2 captures its substrate, hemoglobin, via a unique motif.

Falcipain-2 (FP2) is a papain family cysteine protease and important hemoglobinase of erythrocytic Plasmodium falciparum parasites. Inhibitors of FP2 block hemoglobin hydrolysis and parasite development, suggesting that this enzyme is a promising target for antimalarial chemotherapy. FP2 and related plasmodial cysteine proteases have an unusual 14-aa motif near the C terminus of the catalytic domain.

The extended interactions and Gla domain of blood coagulation factor Xa.

The serine protease factor Xa (FXa) is inhibited by ecotin with picomolar affinity. The structure of the tetrameric complex of ecotin variant M84R (M84R) with FXa has been determined to 2.8 A.