1sgc: Difference between revisions

Revision as of 16:01, 21 February 2008

THE 1.8 ANGSTROMS STRUCTURE OF THE COMPLEX BETWEEN CHYMOSTATIN AND STREPTOMYCES GRISEUS PROTEASE A. A MODEL FOR SERINE PROTEASE CATALYTIC TETRAHEDRAL INTERMEDIATES

OverviewOverview

The naturally occurring serine protease inhibitor, chymostatin, forms a hemiacetal adduct with the catalytic Ser195 residue of Streptomyces griseus protease A. Restrained parameter least-squares refinement of this complex to 1.8 A resolution has produced an R index of 0 X 123 for the 11,755 observed reflections. The refined distance of the carbonyl carbon atom of the aldehyde to O gamma of Ser195 is 1 X 62 A. Both the R and S configurations of the hemiacetal occur in equal populations, with the end result resembling the expected configuration for a covalent tetrahedral product intermediate of a true substrate. This study strengthens the concept that serine proteases stabilize a covalent, tetrahedrally co-ordinated species and elaborates those features of the enzyme responsible for this effect. We propose that a major driving force for the hydrolysis of peptide bonds by serine proteases is the non-planar distortion of the scissile bond by the enzyme, which thereby lowers the activation energy barrier to hydrolysis by eliminating the resonance stabilization energy of the peptide bond.

About this StructureAbout this Structure

1SGC is a Single protein structure of sequence from Streptomyces chryseus with as ligand. Full crystallographic information is available from OCA.

ReferenceReference

The 1.8 A structure of the complex between chymostatin and Streptomyces griseus protease A. A model for serine protease catalytic tetrahedral intermediates., Delbaere LT, Brayer GD, J Mol Biol. 1985 May 5;183(1):89-103. PMID:3892018

Page seeded by OCA on Thu Feb 21 15:01:11 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

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-[[Image:1sgc.gif|left|200px]]<br /><applet load="1sgc" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1sgc.gif|left|200px]]<br /><applet load="1sgc" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1sgc, resolution 1.8&Aring;" />
 '''THE 1.8 ANGSTROMS STRUCTURE OF THE COMPLEX BETWEEN CHYMOSTATIN AND STREPTOMYCES GRISEUS PROTEASE A. A MODEL FOR SERINE PROTEASE CATALYTIC TETRAHEDRAL INTERMEDIATES'''<br />
 ==Overview==
-The naturally occurring serine protease inhibitor, chymostatin, forms a, hemiacetal adduct with the catalytic Ser195 residue of Streptomyces, griseus protease A. Restrained parameter least-squares refinement of this, complex to 1.8 A resolution has produced an R index of 0 X 123 for the, 11,755 observed reflections. The refined distance of the carbonyl carbon, atom of the aldehyde to O gamma of Ser195 is 1 X 62 A. Both the R and S, configurations of the hemiacetal occur in equal populations, with the end, result resembling the expected configuration for a covalent tetrahedral, product intermediate of a true substrate. This study strengthens the, concept that serine proteases stabilize a covalent, tetrahedrally, co-ordinated species and elaborates those features of the enzyme, responsible for this effect. We propose that a major driving force for the, hydrolysis of peptide bonds by serine proteases is the non-planar, distortion of the scissile bond by the enzyme, which thereby lowers the, activation energy barrier to hydrolysis by eliminating the resonance, stabilization energy of the peptide bond.
+The naturally occurring serine protease inhibitor, chymostatin, forms a hemiacetal adduct with the catalytic Ser195 residue of Streptomyces griseus protease A. Restrained parameter least-squares refinement of this complex to 1.8 A resolution has produced an R index of 0 X 123 for the 11,755 observed reflections. The refined distance of the carbonyl carbon atom of the aldehyde to O gamma of Ser195 is 1 X 62 A. Both the R and S configurations of the hemiacetal occur in equal populations, with the end result resembling the expected configuration for a covalent tetrahedral product intermediate of a true substrate. This study strengthens the concept that serine proteases stabilize a covalent, tetrahedrally co-ordinated species and elaborates those features of the enzyme responsible for this effect. We propose that a major driving force for the hydrolysis of peptide bonds by serine proteases is the non-planar distortion of the scissile bond by the enzyme, which thereby lowers the activation energy barrier to hydrolysis by eliminating the resonance stabilization energy of the peptide bond.
 ==About this Structure==
-SGC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_chryseus Streptomyces chryseus] with CST as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1SGC OCA].
+SGC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_chryseus Streptomyces chryseus] with <scene name='pdbligand=CST:'>CST</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SGC OCA].
 ==Reference==
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 [[Category: Single protein]]
 [[Category: Streptomyces chryseus]]
-[[Category: Brayer, G.D.]]
+[[Category: Brayer, G D.]]
-[[Category: Delbaere, L.T.J.]]
+[[Category: Delbaere, L T.J.]]
 [[Category: CST]]
 [[Category: hydrolase (serine proteinase)]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 02:21:55 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:01:11 2008''