英语翻译Cell Growth Conditions and Protein Purification.FNR wasp

英语翻译Cell Growth Conditions and Protein Purification.FNR waspurified from an E.coli B derivative,PK22 (crp-bs990 andDfnr),carrying fnr under control of the inducible T7 promoteron the plasmid pPK823 (6).For purification of the 57Fecontainingform of FNR for Mo¨ssbauer spectroscopy,theinoculum was prepared by centrifuging 10 ml of overnightculture,grown in Luria broth (7),containing 0.2% glucose and50 mgyml ampicillin,at 5,000 3 g for 5 min.The cell pellet wasthen added to 1 liter of the 57Fe-enriched M9 minimal medium(7) prepared as follows:The M9 salts solution was passedthrough a Chelex 100 (200–400 mesh) column (40 g of resinper 1 liter of medium),which eliminated naturally abundant56Fe from the medium as shown by inductively coupled plasmaatomic emission spectroscopy.57Fe (95.9% abundance) wasadded to the medium to a final concentration of 20 mM asferrous ethylenediammonium sulfate (brought to pH '3 withNaOH).The following reagent grade compounds were alsoadded at the indicated final concentrations:0.1 mM CaCl2,1.0mM MgSO4,0.2% casamino acid,0.2% glucose,4 mgymlvitamin B1,and 50 mgyml ampicillin.When cultures enrichedin 57Fe or naturally abundant Fe reached an OD600 of 0.35–0.60,FNR synthesis was induced as described (3).Followinginduction of FNR synthesis,cell cultures were sparged withargon at 4°C for 14 hr,which appeared to improve recovery ofFNR as compared with our previous results.Purification ofFNR from cell extracts was carried out under anaerobicconditions as described (3) except that DTT was added to thepurification buffer to a final concentration of 1 mM.Tominimize any exposure to oxygen,samples were manipulatedeither under a stream of copper scrubbed-argon gas or in ananaerobic chamber (Coy),which had an atmosphere of 5%CO2y5% H2y90% N2.觉得多的话只翻译这两句可以不,说了不要翻译软件翻译的东西,太乱了The M9 salts solution was passedthrough a Chelex 100 (200–400 mesh) column (40 g of resinper 1 liter of medium),which eliminated naturally abundant56Fe from the medium as shown by inductively coupled plasmaatomic emission spectroscopy.