1gwd

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spinqualitylabelsall models 1gwd, resolution 1.77Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

TRI-IODIDE DERIVATIVE OF HEN EGG-WHITE LYSOZYME

Overview

A series of experiments performed at Cu Kalpha wavelength on in-house X-ray equipment are presented which investigate two possibilities for enhancing the experimental phasing signal by means of (i) triiodide/iodide soaks using KI/I(2) and (ii) combinations of counter-ions introduced using the short cryosoak method. Triiodide-derivative crystal structures for five test proteins have been refined and reveal that iodine can bind as polyiodide and single iodide ions through hydrophobic and hydrogen-bonding interactions both at the molecular surface and in intramolecular and intermolecular cavities. In three cases, the structures could be automatically determined with autoSHARP using in-house SAD and SIRAS data. The investigation of combinatorial counter-ion replacement using multiple salts with Na(+) and Cs(+) as cations and I(-) and Cl(-) as anions reveals that, for the case of hen egg-white lysozyme, significant improvement in phasing signal is obtained by the combined use of salts compared with SIRAS methods using native and single short-soak derivative data sets.

About this Structure

1GWD is a Single protein structure of sequence from Gallus gallus with , , , and as ligands. Active as Lysozyme, with EC number 3.2.1.17 Known structural/functional Site: . Full crystallographic information is available from OCA.

Reference

Triiodide derivatization and combinatorial counter-ion replacement: two methods for enhancing phasing signal using laboratory Cu Kalpha X-ray equipment., Evans G, Bricogne G, Acta Crystallogr D Biol Crystallogr. 2002 Jun;58(Pt 6 Pt 2):976-91. Epub, 2002 May 29. PMID:12037300

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