RE: [ccp4bb]: keep Fe2+ in protein from oxidation

[Patrick Shaw Stewart]

Hi Rongjin   You question gives me the opportunity to announce the winner of our competition for the best new crystallization technique or method.  It was won this year by Bret Dillard at the University of Georgia.  Bret crystallized and is solving the structure of an iron-containing protein from Pyrococcus.  The protein had previously been crystallized with zinc in place of the iron, but Bret collected data in the absence of oxygen from the native protein containing iron.  Brett used the microbatch-under-oil technique - which in itself gives significant protection against oxidation - using a robot in an anaerobic chamber.   You can find Bret’s entry at http://www.douglas.co.uk/presentations/winner2.htm   I hope this is helpful.   Patrick   --  [EMAIL PROTECTED]    Douglas Instruments Ltd.  DouglasHouse, EastGarston, Hungerford, Berkshire, RG177HD, UK Directors: Peter Baldock, Patrick Shaw Stewart, James Smith http://douglas.co.uk or http://www.douglasinstruments.com Tel: 44 (0) 148-864-9090    US toll-free 1-877-225-2034 From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rongjin Guan Sent: 11 September 2006 20:57 To: ccp4bb Subject: [ccp4bb]: keep Fe2+ in protein from oxidation   Dear All,   I am working on a protein containing Fe2+. Oxidation of Fe2+ to Fe3+ is a problem for this protein during purification and crysatllization, which makes the protein to convert to Apo enzyme. On the native gel, the Apo protein shows a smear in stead of a signle band, indicating a very loose comformation of the Apo protein.   we are looking for suggestions or good reducing reagents to prevent the oxidation. Any suggestions and comments are welcome.   Thanks   Rongjin Guan NIDDK, NIH   Rongjin Guan 2006-09-11