Sandbox 42
From Proteopedia
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== Active site and Binding == | == Active site and Binding == | ||
| - | Hen white lysozyme's substrate binding site accomodates six residue oligosaccharides. Glu 35 and Asp 52 are the enzyme's active site residues. These residues have distinctly different microenvironments which are critical for their catalytic action. Asp 52 forms hydrogen bonds with surrounding residues and is negatively charged allowing for electrostatic stabilization. Glu 35 conversely is surrounded by hydrophobic residues and its side chain stays protonated allowing for acid catalysis. Catalysis proceeds through the formation of a covalent intermediate. | + | Hen white lysozyme's substrate binding site accomodates six residue oligosaccharides. Glu 35 and Asp 52 are the enzyme's active site residues. These residues have distinctly different microenvironments which are critical for their catalytic action. Asp 52 forms hydrogen bonds with surrounding residues including Asn46, Asp48, Ser50 and Asn59 on the anti-parallel beta-sheet and is negatively charged allowing for electrostatic stabilization of the reaction intermediate.<ref> PMID:19605465 </ref> Glu 35 conversely is surrounded by hydrophobic residues and its side chain stays protonated allowing for acid catalysis. Catalysis proceeds through the formation of a covalent intermediate. |
== References == | == References == | ||
<references/> | <references/> | ||
Revision as of 12:37, 29 October 2010
| Please do NOT make changes to this Sandbox. Sandboxes 30-60 are reserved for use by Biochemistry 410 & 412 at Messiah College taught by Dr. Hannah Tims during Fall 2012 and Spring 2013. |
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Contents |
Overview
The primary catalytic action of the enzyme lysozyme is to hydrolyze β(1→4) glycosidic linkages found in bacterial cell walls.[1] More specifically, lysozyme hydrolyzes the linkages from N-acetylmuramic acid to N-acetylglucosamine which occur in peptidoglycans of the cell wall. The small 14.3 kD Hen egg white lysozyme is one of the most widely studied lysozymes.
Secondary structure
Hen egg white lysozyme is formed from one polypetide chain 129 amino acids in length. 4 disulfide bonds are involved in folding of the chain.
Distribution of residue polarity
Active site and Binding
Hen white lysozyme's substrate binding site accomodates six residue oligosaccharides. Glu 35 and Asp 52 are the enzyme's active site residues. These residues have distinctly different microenvironments which are critical for their catalytic action. Asp 52 forms hydrogen bonds with surrounding residues including Asn46, Asp48, Ser50 and Asn59 on the anti-parallel beta-sheet and is negatively charged allowing for electrostatic stabilization of the reaction intermediate.[2] Glu 35 conversely is surrounded by hydrophobic residues and its side chain stays protonated allowing for acid catalysis. Catalysis proceeds through the formation of a covalent intermediate.
References
- ↑ http://lysozyme.co.uk/
- ↑ Ose T, Kuroki K, Matsushima M, Maenaka K, Kumagai I. Importance of the hydrogen bonding network including Asp52 for catalysis, as revealed by Asn59 mutant hen egg-white lysozymes. J Biochem. 2009 Nov;146(5):651-7. Epub 2009 Jul 15. PMID:19605465 doi:10.1093/jb/mvp110
