Flexible synthesis and biological evaluation of novel 5-deoxyadenophorine analogues.

Adenophorine and its 5-deoxy analogue have been identified as natural iminosugars with efficient glycosidase inhibitory effects. The syntheses and biological evaluation of two new series of 5-deoxyadenophorine analogues in their racemic form are reported. The compounds 12e and 13d bearing a C11 and C7 alkyl chain, respectively, were found to be potent inhibitors of the beta-glucosidase from almond with Ki near to 60 microM.

Bivalent Fv antibody fragments obtained by substituting the constant domains of a fab fragment with heterotetrameric molybdopterin synthase.

The antibody Fv fragment is the smallest functional unit of an antibody but for practical use, the VH/VL interface requires stabilization, which is usually accomplished by a peptide linker that joins the two variable domains to form a single chain Fv fragment (scFv). An alternative format to scFv is proposed that (i) allows stabilization of the Fv fragment, and (ii) restores the bivalency of the antibody as a pseudo-F(ab')2 format. This new antibody fragment was constructed by replacing the CHI and CL domains of the Fab fragment with heterotetrameric molybdopterin synthase (MPTS).

Comparison of three microbial hosts for the expression of an active catalytic scFv.

Antibodies represent an interesting protein framework on which catalytic functions can be grafted. In previous studies, we have reported the characterization of the catalytic antibody 4B2 obtained on the basis of the "bait and switch" strategy which catalyzes two different chemical reactions: the allylic isomerization of beta,gamma-unsaturated ketones and the Kemp elimination. We have cloned the antibody 4B2 and expressed it as a single-chain Fv (scFv) fragment in different expression systems, Escherichia coli and two yeasts species, in order to elicit the most suitable system to study its catalytic activity.

Functional mimicry between anti-Tendamistat antibodies and alpha-amylase.

A proteinaceous inhibitor of alpha-amylase, Tendamistat, was evaluated as an immunogen to induce antibodies that mimic the enzyme activity and to investigate a new strategy to produce catalytic antibodies. Anti-Tendamistat polyclonal antibodies (pAbs) were shown to cross-react with acarbose, a strong carbohydrate inhibitor of alpha-amylases, and the alpha-amylase carbohydrate substrates, maltotetraose and maltoheptaose. Catalytic features of pAbs were characterized after denaturing natural serum alpha-amylase by treatment at pH 10 and in the presence of EDTA.