1GWA

Triiodide derivative of porcine pancreas elastase

Summary for 1GWA

• Entry DOI: 10.2210/pdb1gwa/pdb
• Related: 1B0E 1BMA 1BTU 1C1M 1E34 1E35 1E36 1E37 1E38 1E9H 1EAI 1EAS 1EAT 1EAU 1ELA 1ELB 1ELC 1ELD 1ELE 1ELF 1ELG 1ESA 1ESB 1EST 1FLE 1FZZ 1GVK 1H9L 1HAX 1HAY 1HAZ 1HB0 1HV7 1INC 1JIM 1LVY 1NES 1QGF 1QIX 1QNJ 1QR3 2EST 3EST 4EST 5EST 6EST 7EST 8EST 9EST
• Descriptor: ELASTASE 1, CALCIUM ION, SULFATE ION, ... (5 entities in total)
• Functional Keywords: hydrolase, serine protease, zymogen
• Biological source: SUS SCROFA (PIG)
• Total number of polymer chains: 1
• Total formula weight: 28983.95

Authors

Evans, G.,Bricogne, G. (deposition date: 2002-03-13, release date: 2002-06-06, Last modification date: 2019-05-08)

Primary citation

Evans, G.,Bricogne, G.
Triiodide Derivatization and Combinatorial Counter-Ion Replacement: Two Methods for Enhancing Phasing Signal Using Laboratory Cu Kalpha X-Ray Equipment
Acta Crystallogr.,Sect.D, 58:976-, 2002

PubMed Abstract: 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.

PubMed: 12037300
DOI: 10.1107/S0907444902005486

Experimental method

X-RAY DIFFRACTION (1.85 Å)