Half-Barrels Derived from a (β/α)8 Barrel β-Glycosidase Undergo an Activation Process.

The evolution of (β/α)8 barrel proteins is currently thought to have involved the fusion of two (β/α)4 half-barrels, thereby conferring stability on the protein structure. After the formation of a whole (β/α)8 barrel, this structure could evolve and diverge to form fully active enzymes. Interestingly, we show here that isolated (β/α)4 half-barrels derived from the N- and C-terminal domains of the β-glucosidase Sfβgly (Sfβgly-N: residues 1 to 265; Sfβgly-C: residues 266 to 509) undergo an activation process, which renders them catalytically active.

The 3D structure and function of digestive cathepsin L-like proteinases of Tenebrio molitor larval midgut.

Cathepsin L-like proteinases (CAL) are major digestive proteinases in the beetle Tenebrio molitor. Procathepsin Ls 2 (pCAL2) and 3 (pCAL3) were expressed as recombinant proteins in Escherichia coli, purified and activated under acidic conditions. Immunoblot analyses of different T.

Heterologous expression in Escherichia coli of Neurospora crassa neutral trehalase as an active enzyme.

Neutral trehalase from Neurospora crassa was expressed in Escherichia coli as a polypeptide of approximately 84 kDa in agreement with the theoretical size calculated from the corresponding cDNA. The recombinant neutral trehalase, purified by affinity chromatography exhibited a specific activity of 80-150 mU/mg protein. Optima of pH and temperature were 7.

Identification and domain mapping of Dictyostelium discoideum type-1 protein phosphatase inhibitor-2.

The protein phosphatase type-1 catalytic subunit (PP1c) does not exist freely in the cell and its activity must be very strictly controlled. Several protein inhibitors of PP1c have been described including the classical mammalian inhibitor-1 (I-1) and inhibitor-2 (I-2). Association of these inhibitors with PP1c appears to involve multiple contacts and in the case of I-2 no less than five I-2 interaction subdomains have been proposed.