Prolyl Endopeptidase: Difference between revisions

Line 16:

From observed interactions between the β-propeller and catalytic domains several possible substrate binding mechanism have been proposed.

The ~~first~~ theory of substrate binding was that the substrate would be able to travel through the central channel in the β-propeller domain to the active site. This theory was proved less likely as the central channel is only 4Å wide in its relaxed state compared to the medium length peptides catalyzed by PEP which are 6-12Å in diameter.<ref name="Shan1">PMID:15245330</ref> This theory is still possible as a conformational change could allow the much larger substrate to travel through the β-propeller domain.

The initial theory of substrate binding was that the substrate would be able to travel through the central channel in the β-propeller domain to the active site. This theory was proved less likely as the central channel is only 4Å wide in its relaxed state compared to the medium length peptides catalyzed by PEP which are 6-12Å in diameter.<ref name="Shan1">PMID:15245330</ref> This theory is still possible as a conformational change could allow the much larger substrate to travel through the β-propeller domain.

~~A newer~~ proposed mechanism of substrate binding is that the β-propeller domain acts as a gate to the active site and that the whole domain moves during a conformational change. This theory has gathered support as a structure for the PEP of ''Sphingomonas capsulata'' clearly shows the β-propeller in an open configuration connected to the catalytic domain by two peptide strands on the same side of the enzyme forming a hinge.<ref name="Gass"/>

Another proposed mechanism of substrate binding is that the β-propeller domain acts as a gate to the active site and that the whole domain moves during a conformational change. This theory has gathered support as a structure for the PEP of ''Sphingomonas capsulata'' clearly shows the β-propeller in an open configuration connected to the catalytic domain by two peptide strands on the same side of the enzyme forming a hinge.<ref name="Gass"/>

Both mechanistic binding theories account for the observed activity of PEP as being limited to acting on peptides of less than 30 ~~residues~~.

Both mechanistic binding theories account for the observed activity of PEP as being limited to acting on small peptides of less than 30 amino acids.

=== Inhibition ===

Prolyl Endopeptidase: Difference between revisions

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@@ Line 16: / Line 16: @@
 From observed interactions between the β-propeller and catalytic domains several possible substrate binding mechanism have been proposed.
-The first theory of substrate binding was that the substrate would be able to travel through the central channel in the β-propeller domain to the active site. This theory was proved less likely as the central channel is only 4Å wide in its relaxed state compared to the medium length peptides catalyzed by PEP which are 6-12Å in diameter.<ref name="Shan1">PMID:15245330</ref> This theory is still possible as a conformational change could allow the much larger substrate to travel through the β-propeller domain.
+The initial theory of substrate binding was that the substrate would be able to travel through the central channel in the β-propeller domain to the active site. This theory was proved less likely as the central channel is only 4Å wide in its relaxed state compared to the medium length peptides catalyzed by PEP which are 6-12Å in diameter.<ref name="Shan1">PMID:15245330</ref> This theory is still possible as a conformational change could allow the much larger substrate to travel through the β-propeller domain.
-A newer proposed mechanism of substrate binding is that the β-propeller domain acts as a gate to the active site and that the whole domain moves during a conformational change. This theory has gathered support as a structure for the PEP of ''Sphingomonas capsulata'' clearly shows the β-propeller in an open configuration connected to the catalytic domain by two peptide strands on the same side of the enzyme forming a hinge.<ref name="Gass"/>
+Another proposed mechanism of substrate binding is that the β-propeller domain acts as a gate to the active site and that the whole domain moves during a conformational change. This theory has gathered support as a structure for the PEP of ''Sphingomonas capsulata'' clearly shows the β-propeller in an open configuration connected to the catalytic domain by two peptide strands on the same side of the enzyme forming a hinge.<ref name="Gass"/>
-Both mechanistic binding theories account for the observed activity of PEP as being limited to acting on peptides of less than 30 residues.
+Both mechanistic binding theories account for the observed activity of PEP as being limited to acting on small peptides of less than 30 amino acids.
 === Inhibition ===