State of imidazole side chain of hen lysozyme modified with histamine and Japanese quail lysozyme. A study by immobilized metal ion affinity chromatography.
Hen lysozyme modified with histamine (HML) and Japanese quail lysozyme (JQL) were treated with immobilized metal ion affinity chromatography to analyze the states of their imidazole groups. When Ni(II) was used as the metal ion immobilized, JQL was strongly retained in a Ni(II)-chelating Sepharose column, while hen lysozyme and HML were hardly retained in the same column. All of these lysozymes have a histidine imidazole group at the 15th position, while JQL has an additional histidine imidazole group at the 103rd position and HML has an additional imidazole group covalently attached to Asp101. Thus, I concluded that the imidazole group at the 103rd position of JQL is exposed to the solvent and recognized by the metal ion, but that the imidazole group attached to Asp101 in HML is localized to a hydrophobic region and not recognized by the metal ion.
Fukamizo
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Laboratory of Biophysical Chemistry, Faculty of Agriculture, Kinki University, Nara, Japan. fukamizo@nara.kindai.ac.jp
D000818:Animals; D002413:Cations, Divalent; D002645:Chickens; D002846:Chromatography, Affinity; D003370:Coturnix; D005260:Female; D006632:Histamine / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D008670:Metals; D009113:Muramidase / Q000737:chemistry*