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PDBsum entry 1v6d
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References listed in PDB file
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Key reference
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Title
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Secondary binding site of trypsin: revealed by crystal structure of trypsin-Peptide complex.
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Authors
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N.Shamaladevi,
V.Pattabhi.
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Ref.
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J Biomol Struct Dyn, 2005,
22,
635-642.
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PubMed id
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Abstract
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Designed synthetic heterochiral peptides, when added to porcine trypsin,
resulted in reduction of enzyme activity. The crystal structure of a complex
formed between porcine trypsin and a heterochiral hepta peptide
Boc-Pro-DAsp-Aib-Leu-Aib-Leu-Ala-NHMe has been determined at 1.9 A resolution.
The hepta peptide does not bind at the active site, but is located in the
interstitial region, and interacts with the calcium-binding loop (residues
60-80). The bound peptide interacts with the active site residue Ser195 through
an acetate ion, and with Lys 60 mediated by water molecules. The structure, when
compared with the other trypsin-peptide complexes, suggests that the flexibility
of surface loops, concerted movement of the loops towards the active site, and
the interaction of the bound peptide with Lys 60, may be responsible for the
reduction in enzyme activity. This study provides a structural evidence for the
earlier biochemical observation regarding the role of surface loops in the
catalysis of the enzyme.
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