Re: Pepsyn EDT/DTT

Richard Laursen (laursen@bu.edu)
Tue, 17 Mar 1998 09:48:39 -0400

A couple of years ago Jean LeFebvre described on the ABRF bulletin board a
cleavage cocktail that uses DTT as a low-odor replacement for the
scavengers EDT and thioanisole. Subsequently we did a study with a number
of peptides comparing this reagent [which we call reagent L (for LeFebvre)]
with reagents K and R and some other cocktails. The results were presented
at the American Peptide Society meeting last year (Duly et al.). The
bottom line is that reagent L seems to work at least as well as any of the
other reagents--and it doesn't smell. Reagent L has the composition

88% TFA
2% Triisopropylsilane
5% Dithiothreitol
5% Water

Richard Laursen

--------------------------

>And not only odor. I know at least one significant difference between
>DTT and EDT -- EDT readily reacts with benzophenone (or Bpa) , but DTT
>not. This is the reason why EDT can not be used for scavenging during
>the TFA cleavage of the Bpa contained peptide. But, from the other
>side, is DTT as good as EDT? Did anybody test and compare the efficiency
>of DTT as a scavenger to EDT? I have a concern that EDT may be more
>efficient than DTT. An often trade-off.
>Michael Breslav
>R.W. Johnson PRI
>Spring House, PA 19477-0776
>(215) 628 5761
>
>> ----------
>> From: anaspec[SMTP:anaspec@shell11.ba.best.com]
>> Sent: Monday, March 16, 1998 1:07 PM
>> To: Recipients of ABRF List
>> Subject: Re: Pepsyn: Rainin symphony
>>
>> Dear Henriette,
>>
>> To avoid odor from EDT, we have changed to DTT. DTT is a solid and
>> the
>> smell is much less compared to EDT.
>>
>> Anita Hong
>>
>> AnaSpec, Inc.
>> 2149 O'Toole Avenue, Suite F
>> San Jose, CA 95131
>> (408)452-5055 (phone)
>> (408)452-5059 (fax)
>> e-mail: service@anaspec.com
>> home-page: www.anaspec.com
>>

Richard A. Laursen
Department of Chemistry
Boston University
590 Commonwealth Ave.
Boston, MA 02215
Tel (617) 353-2491; FAX (617) 353-6466
email: <laursen@bu.edu>