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Hen Egg-White Lysozyme (HEWL) complexed with two methyl-functionalised Anderson-Evans polyoxometalates
Structural highlights
FunctionLYSC_CHICK Lysozymes have primarily a bacteriolytic function; those in tissues and body fluids are associated with the monocyte-macrophage system and enhance the activity of immunoagents. Has bacteriolytic activity against M.luteus.[1] Publication Abstract from PubMedInteractions between the protein Hen Egg White Lysozyme (HEWL) and three different hybrid Anderson-Evans polyoxometalate clusters - AE-NH2 (delta-[MnMo(6)O(18)(OCH(2))(3)CNH(2)(2)](3-)), AE-CH3 (delta-[MnMo(6)O(18)(OCH(2))(3)CCH(3)(2)](3-)) and AE-Biot (delta-[MnMo(6)O(18)(OCH(2))(3)CNHCOC(9)H(15)N(2)OS(2)](3-)) - were studied via tryptophan fluorescence spectroscopy and single crystal X-ray diffraction. Quenching of tryptophan fluorescence was observed in the presence of all three hybrid polyoxometalate clusters (HPOMs), but the extent of quenching and the binding affinity were greatly dependent on the nature of the organic groups attached to the cluster. Control experiments further revealed the synergistic effect of the anionic polyoxometalate core and organic ligands towards enhanced protein interactions. Furthermore, the protein was co-crystallised with each of the three HPOMs, resulting in four different crystal structures, thus allowing for the binding modes of HPOM-protein interactions to be investigated with near-atomic precision. All crystal structures displayed a unique mode of binding of the HPOMs to the protein, with both functionalisation and the pH of the crystallisation conditions influencing the interactions. From the crystal structures, it was determined that HPOM-protein non-covalent complexes formed through a combination of electrostatic attraction between the polyoxometalate cluster and positively charged surface regions of HEWL, and direct and water-mediated hydrogen bonds with both the metal-oxo inorganic core and the functional groups of the ligand, where possible. Hence, functionalisation of metal-oxo clusters shows great potential in tuning their interactions with proteins, which is of interest for several biomedical applications. Fine-tuning non-covalent interactions between hybrid metal-oxo clusters and proteins.,Lentink S, Salazar Marcano DE, Moussawi MA, Vandebroek L, Van Meervelt L, Parac-Vogt TN Faraday Discuss. 2023 Aug 11;244(0):21-38. doi: 10.1039/d2fd00161f. PMID:37102318[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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