Bicyclic peptides with optimized ring size inhibit human plasma kallikrein and its orthologs while sparing paralogous pr

April 13, 2012
Bicyclic peptides with optimized ring size inhibit human plasma kallikrein and its orthologs while sparing paralogous proteases

(Phys.org) -- New drug candidates require testing in animal models prior to approval for clinical use. A recently developed antagonist based on a bicyclic peptide inhibited the human serine protease plasma kallikrein potently and selectively. However, the inhibitor was ‘too’ selective, not inhibiting murine plasma kallikrein which prevented its testing in animal models. Researchers led by Christian Heinis have developed bicyclic peptides that inhibit both human and murine plasma kallikrein, but not any paralogous proteases; their work is reported in ChemMedChem.

"We compared structural models of target (and related non-target) proteases to identify conserved regions in the vicinity of the active site, and modulated the loop size of our libraries of peptide macrocycles accordingly," says Heinis on behalf of his team at the Swiss Federal Institute of Technology in Lausanne and colleagues John Tite (Bicyclic Therapeutics) and Greg Winter (Laboratory of Molecular Biology; both Cambridge, UK). "From these libraries, we were able to isolate potent bicyclic peptide inhibitors of human, rat and monkey plasma kallikrein that do not inhibit related human serum proteases."

Based on structural considerations, the authors hypothesize that the length of the peptide loops may influence specificity. By modulating the loop size of the peptide macrocycles, they succeeded in selecting potent human plasma kallikrein inhibitors with the desired specificity profile. Heinis states further that "...the bicyclic combine key qualities of antibody therapeutics (high affinity and specificity) and advantages of small-molecule drugs and may offer an attractive format for the development of therapeutics." The authors conclude that this strategy will likely facilitate the use of peptide macrocycles in animal models, while avoiding unwanted off-target activities in the clinic.

Explore further: First-ever covalent irreversible inhibition of a protease central to hepatitis C infection

More information: Christian Heinis, Bicyclic Peptides with Optimized Ring Size Inhibit Human Plasma Kallikrein and its Orthologues While Sparing Paralogous Proteases, ChemMedChem, dx.doi.org/10.1002/cmdc.201200071

Related Stories

Active compounds against Alzheimer's disease

January 12, 2012

More than half of all cases of dementia in the elderly can be attributed to Alzheimer's disease. Despite vast research efforts, an effective therapy has not been developed, and treatment consists of dealing with the symptoms. ...

Understanding the APJ Receptor Binding Site

June 1, 2010

(PhysOrg.com) -- Apelin is a recently discovered peptide that binds to the apelin (or APJ) G-protein-coupled receptor. Apelin-13 (NH2-QRPRLSHKGPMPF-COOH), one of several cleavage products of the proprotein form of the apelin ...

Recommended for you

Scientists develop new theory of molecular evolution

October 23, 2017

Researchers from the University of Colorado Anschutz Medical Campus and the University College London have developed a new theory of molecular evolution, offering insights into how genes function, how the rates of evolutionary ...

Austrian researchers facilitate lipid data analysis

October 23, 2017

No lipids, no life. In all organisms, lipids form cell walls, store energy and release it when necessary, and play an important role in cell signalling. It has been proved that changes in the composition of lipids play a ...

Close up view of growing polymer chain show jump steps

October 20, 2017

(Phys.org)—A team of researchers at Cornell University has devised a means for watching as a polymer chain grows after application of a catalyst. In their paper published in the journal Science, the team explains how they ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.