<HTML> <HEAD> <TITLE>DGK Membrane Preparation</TITLE> </HEAD> <BODY> <P><CENTER>[ <A HREF=http://www.musc.edu/bcmb/ceramide/protocols/toc.html>TOC</A> | <A HREF=http://www.musc.edu/bcmb/ceramide/protocols/apoptosis.html>Apoptosis</A> | <A HREF=http://www.musc.edu/bcmb/ceramide/protocols/biochemistry.html>Biochemistry</A> | <A HREF=http://www.musc.edu/bcmb/ceramide/protocols/cbcc.html>CBCC</A> | <A HREF=http://www.musc.edu/bcmb/ceramide/protocols/lipid.html>Lipid</A> | <A HREF=http://www.musc.edu/bcmb/ceramide/protocols/mbg.html>MBG</A> | <A HREF=http://www.musc.edu/bcmb/ceramide/protocols/yeast.html>Yeast</A> | <A HREF=http://www.musc.edu/bcmb/ceramide/protocols/misc.html>Misc</A> ]<BR> <HR></CENTER> <H2><CENTER>DGK Membrane Preparation</CENTER> </H2> <BR> <BR> <BR> Contributor: Suprya Jayadev<BR> Date: Dec. 10, 1992<BR> <BR> <BR> <BR> <B>Reagents</B>:<BR> <BR> Bacterial strain<BR> <I>E. </I>coli N4830/pJW10<BR> <BR> LB amp media<BR> 50 µg/ml ampicillin<BR> <BR> High salt buffer<BR> for 1 L<BR> 50 mM KH2PO4 6.8 g<BR> 150 mM KCl 11.18 g<BR> 50 mM sodium pyrophosphate (Na4P2O7-10H2O) 22.3 g<BR> 5 mM Na2 EDTA 1.86 g<BR> 5 mM b-mercaptoethanol 390 µl<BR> <BR> TNE buffer for 1 L<BR> 25 mM Tris 3.03 g<BR> 100 mM NaCl 5.84 g<BR> 1 mM Na2 EDTA (pH 8.0) 0.37 g<BR> 5 mM b-mercaptoethanol 390 µl<BR> <BR> TEM buffer for 1 L<BR> 25 mM Tris 3.03 g<BR> 1 mM Na2 EDTA (pH 8.0) 0.37 g<BR> 5 mM b-mercaptoethanol 390 µl<BR> <BR> <HR><BR> 1) Thaw cells.<BR> <BR> 2) Innoculate 10 ml of LB amp media and grow cells overnight @ 32°C<BR> <BR> 3) Aliquot 1 ml of culture for glycerol permeant, store at -80°C.<BR> <BR> 4) Pour remaining preculture into 300 ml of LB broth.<BR> <BR> --> NOTE: Set aside some LB in order to zero the spectrophotometer.<BR> <BR> 5) Grow cells at 32°C checking OD600 every 1/2 hour.<BR> <BR> 6) When absorbance reaches 1, switch culture to 42°C to induce enzyme activity.<BR> <BR> 7) Grow cells for 1.5 to 2 hours at 42°C.<BR> <BR> 8) Harvest by spinning cells down at 5,000xg for 20 minutes.<BR> <BR> 9) Resuspend pellet in 150 ml of TNE buffer and centrifuge at 5,000xg for 20 minutes.<BR> <BR> --> NOTE: Pellets can be frozen at this point if neccessary.<BR> <BR> 10) Resuspend pellet in 150 ml of high salt buffer.<BR> <BR> 11) Rupture cells using a French press two times.<BR> <BR> --> Settings for French press: 12,000 psi, 762 gauge.<BR> <BR> 12) Spin homogenate at 5,000 rpm (7,000xg) for 15 minutes using the SS-34 rotor.<BR> <BR> -->This step removes any unbroken cells and large debris.<BR> <BR> 13) Pellet membranes by spinning supernatant at 200,000xg for 90 minutes (48,000 rpm in Beckman Ti50.2).<BR> <BR> 14) Resuspend pellet in 5 ml of TNE buffer using a Pasteur pipet, vortex and pass through 18G spinal needle.<BR> <BR> 15) Bring volume up to 150 ml with TNE buffer.<BR> <BR> 16) Spin at 200,000xg for 60 minutes (as above).<BR> <BR> 17) Resuspend in 5 ml of TEM, homogenize 12-15 strokes in order to resuspend completely.<BR> <BR> 18) Do a protein determiniation, should have a concentration of ~10 mg/ml protein.<BR> <BR> 19) Aliquot membrane suspensions and store in -80°C freezer.<BR> <BR> <BR> </BODY> </HTML>