2h9j

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Revision as of 09:30, 21 November 2007

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spinqualitylabelsall models 2h9j, resolution 1.75Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Structure of Hen egg white lysozyme soaked with Ni2-Xylylbicyclam

Overview

Nickel(II)-xylylbicyclam is a potent anti-HIV agent and binds strongly to, the CXCR4 co-receptor. We have investigated configurational equilibria of, Ni(II)-cyclam derivatives, since these are important for receptor, recognition. Crystallographic studies show that both trans and cis, configurations are readily formed: [Ni(cyclam)(OAc)(2)] x H(2)O adopts the, trans-III configuration with axial monodentate acetates, as does, [Ni(benzylcyclam)(NO(3))(2)] with axial nitrate ligands, whereas, [Ni(benzylcyclam)(OAc)](OAc)2 x H(2)O has an unusual folded cis-V, configuration with Ni(II) coordination to bidentate acetate. UV/Vis and, NMR studies show that the octahedral trans-III configuration slowly, converts to square-planar trans-I in aqueous solution. For, Ni(II)-xylylbicyclam, a mixture of cis-V and trans-I configurations was, detected in solution. X-ray diffraction studies showed that crystals of, lysozyme soaked in Ni(II)-cyclam or Ni(II) (2)-xylylbicyclam contain two, major binding sites, one involving Ni(II) coordination to Asp101 and, hydrophobic interactions between the cyclam ring and Trp62 and Trp63, and, the second hydrophobic interactions with Trp123. For Ni(II)-cyclam bound, to Asp101, the cis-V configuration predominates.

About this Structure

2H9J is a Single protein structure of sequence from Gallus gallus with CL, NA, NI and MM5 as ligands. Active as Lysozyme, with EC number 3.2.1.17 Full crystallographic information is available from OCA.

Reference

Configurations of nickel-cyclam antiviral complexes and protein recognition., Hunter TM, McNae IW, Simpson DP, Smith AM, Moggach S, White F, Walkinshaw MD, Parsons S, Sadler PJ, Chemistry. 2007;13(1):40-50. PMID:17120266

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