From: Henryk Eisenberg <Henryk.Eisenberg@weizmann.ac.il>
  To  : vshier@babylon.chem.psu.edu
  Date: Sun, 20 May 2001 12:03:19 +0400

Re:v-bar and Mw

>I am trying to determine the v-bar value for a glycosylated protein.  The
>protein was denatured (6M GnHCl) and placed in either (a) H2O or (b) 50%
>D2O/H2O.  We have acquired data for at a range of concentrations and
>speeds for each sample.   What would be the most appropriate method of
>analyzing this data to determine v-var and Mw?  Thanks,
>
>  Vince
>
>--
>------------------------------------------------
>Vincent K. Shier
>Department of Chemistry
>Penn State University
>152 Davey Laboratory, Box 73
>University Park, PA 16802
>(814) 865-9508
>vks3@psu.edu
>     or
>vshier@chem.psu.edu
>
I SUGGEST YOU CONSULT HENRYK EISENBERG BIOPHYSICAL CHEMISTRY
88 (2000) 1-9. REFERENCES TO EARLIER WORK LISTED THERE.

SMALL CORRECTIONS!   MAY 20, 2001

FOLLOWING JO BUTLER'S COMMENT TO USE THE CASASSA&EISENBERG PROCEDURE
AND MEASURE DENSITY INCREMENTS WITH THE KRATKY-DENSITOMETER PRODUCED
BY ANTON PAAR, I WOULD LIKE TO ADD THE FOLLOWING. 10MG OF PROTEIN, AS
SUGGESTED BY JACK LEBOWITZ, YIELD
A  GOOD RESULT FOR DENSITY MEASUREMENTS, HOWEVER IF ONLY 5MG ARE
AVAILABLE THEY WILL ALSO BE HELPFUL. IN ADDITION, WHATEVER AMOUNT OF
PROTEIN IS USED FOR THE DENSITY DETERMINATION, IT WILL NOT BE AFFECTED,
AND CAN BE REUSED FOR OTHER PURPOSES. I FIND IT HARD TO UNDERSTAND WHY
ANALYTICAL ULTRACENTRIFUGE USERS USE  THE (1-V.BAR.RHO) TERM NEGLECTING
SOLUTE-SOLVENT AND OTHER INTERACTIONS, RATHER THAN THE CORRECT DENSITY
TERM. THIS IS DESCRIBED IN MORE DETAIL IN MY ABOVE BIOPHYSICAL CHEMISTRY
PAPER WHICH YOU CAN TAKE OFF THE NET, OR WRITE TO ME IF YOU DO NOT SUCCEED.
HENRYK (HEINI) EISENBERG, STRUCTURAL BIOLOGY DEPT., WEIZMANN INSTITUTE,
REHOVOT 76100 ISRAEL, EMAIL AS ABOVE.