2B74

T4 Lysozyme mutant L99A at 100 MPa

Summary for 2B74

• Entry DOI: 10.2210/pdb2b74/pdb
• Related: 1B6T 1B6W 1B6X 1B6Y 1B6Z 1B70 1B72 1B73 1B75
• Descriptor: Lysozyme, CHLORIDE ION, BETA-MERCAPTOETHANOL, ... (4 entities in total)
• Functional Keywords: t4 lysozyme, high pressure, cavity, hydrolase
• Biological source: Enterobacteria phage T4
• Cellular location: Host cytoplasm : P00720
• Total number of polymer chains: 1
• Total formula weight: 18586.19

Authors

Collins, M.D.,Quillin, M.L.,Matthews, B.W.,Gruner, S.M. (deposition date: 2005-10-03, release date: 2005-11-08, Last modification date: 2023-08-23)

Primary citation

Collins, M.D.,Hummer, G.,Quillin, M.L.,Matthews, B.W.,Gruner, S.M.
Cooperative water filling of a nonpolar protein cavity observed by high-pressure crystallography and simulation
Proc.Natl.Acad.Sci.Usa, 102:16668-16671, 2005

PubMed Abstract: Formation of a water-expelling nonpolar core is the paradigm of protein folding and stability. Although experiment largely confirms this picture, water buried in "hydrophobic" cavities is required for the function of some proteins. Hydration of the protein core has also been suggested as the mechanism of pressure-induced unfolding. We therefore are led to ask whether even the most nonpolar protein core is truly hydrophobic (i.e., water-repelling). To answer this question we probed the hydration of an approximately 160-A(3), highly hydrophobic cavity created by mutation in T4 lysozyme by using high-pressure crystallography and molecular dynamics simulation. We show that application of modest pressure causes approximately four water molecules to enter the cavity while the protein itself remains essentially unchanged. The highly cooperative filling is primarily due to a small change in bulk water activity, which implies that changing solvent conditions or, equivalently, cavity polarity can dramatically affect interior hydration of proteins and thereby influence both protein activity and folding.

PubMed: 16269539
DOI: 10.1073/pnas.0508224102

Experimental method

X-RAY DIFFRACTION (2.1 Å)