The catalytic mechanism of serine proteases II: The effect of the protein environment in the alpha-chymotrypsin proton relay system.
The proton relay system of alpha-chymotrypsin is analyzed by the INDOISCRF method. The effects of the protein electric and polarization fields are explicitly introduced in the calculations. It is shown that the multicharged structure Ser-His+Asp- is the most sensitive, from an energetic view-point, towards the protein surrounding effects. Variations in the permanent and polarization fields are discussed, as well as the influence of the substrate and one water molecule localized in the active site of the enzyme. The catalytic role of such changes is conjectured.
Longo
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Stamato
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FM
Ferreira
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R
Tapia
O
O
D001665:Binding Sites; D002918:Chymotrypsin / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D004734:Energy Metabolism; D008954:Models, Biological; D011522:Protons; D012697:Serine Endopeptidases; D014867:Water
D011522:Protons; D014867:Water; D010450:Endopeptidases; D012697:Serine Endopeptidases; D002918:Chymotrypsin