1h0i: Difference between revisions

Over the past years, family 18 chitinases have been validated as potential, targets for the design of drugs against human pathogens that contain or, interact with chitin during their normal life cycles. Thus far, only one, potent chitinase inhibitor has been described in detail, the, pseudotrisaccharide allosamidin. Recently, however, two potent, natural-product cyclopentapeptide chitinase inhibitors, argifin and, argadin, were reported. Here, we describe high-resolution crystal, structures that reveal the details of the interactions of these, cyclopeptides with a family 18 chitinase. The structures are examples of, complexes of a carbohydrate-processing enzyme with high-affinity, peptide-based inhibitors and show in detail how the peptide backbone and, side chains mimic the interactions of the enzyme with, chitooligosaccharides. Together with enzymological characterization, the, structures explain why argadin shows an order of magnitude stronger, inhibition than allosamidin, whereas argifin shows weaker inhibition. The, peptides bind to the chitinase in remarkably different ways, which may, explain the differences in inhibition constants. The two complexes provide, a basis for structure-based design of potent chitinase inhibitors, accessible by standard peptide chemistry.

1H0I is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Serratia_marcescens Serratia marcescens] with SO4, RGI and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Chitinase Chitinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.14 3.2.1.14] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1H0I OCA].  

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