Structural Characterization of the Complex between Hen Egg‐White Lysozyme and ZrIV‐Substituted Keggin Polyoxometalate as Artificial Protease |
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| Authors: | Annelies Sap Elke De?Zitter Prof Luc Van?Meervelt Prof Tatjana N Parac‐Vogt |
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| Affiliation: | Department of Chemistry, KU Leuven, Celestijnenlaan 200F box 2404, 3001 Leuven, Heverlee (Belgium) |
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| Abstract: | Successful co‐crystallization of a noncovalent complex between hen egg‐white lysozyme (HEWL) and the monomeric ZrIV‐substituted Keggin polyoxometalate (POM) (Zr1 K1), (Et2NH2)3Zr(PW11O39)] ( 1 ), has been achieved, and its single‐crystal X‐ray structure has been determined. The dimeric ZrIV‐substituted Keggin‐type polyoxometalate (Zr1 K2), (Et2NH2)10Zr(PW11O39)2] ( 2 ), has been previously shown to exhibit remarkable selectivity towards HEWL hydrolysis. The reported X‐ray structure shows that the hydrolytically active ZrIV‐substituted Keggin POM exists as a monomeric species. Prior to hydrolysis, this monomer interacts with HEWL in the vicinity of the previously identified cleavage sites found at Trp28‐Val29 and Asn44‐Arg45, through water‐mediated H‐bonding and electrostatic interactions. Three binding sites are observed at the interface of the negatively charged Keggin POM and the positively charged regions of HEWL at: 1) Gly16, Tyr20, and Arg21; 2) Asn44, Arg45, and Asn46; and 3) Arg128. |
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| Keywords: | co‐crystallization enzymes interaction modes lysozymes polyoxometalates |
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