> I want to buy a short peptide that forms a helical structure either in
aqueous or organic solvent. The purpose is that I would like to use it as a
standard compound for getting 3D NMR structure.
>
> Could someone tell me which peptide is good and where I can buy it?
>
Frank,
I used to know this, so I ran your question past John Osterhaut (He's
currently in Arizona, formerly of the Rowland Institute, spends his life
designing peptides that form structures other than helices, and so knows
the helix peptides without being biased).
>Rogerrrr,
>
>
>All the short peptides I know about form about 50% helix which makes them
>not so good in the NOE quantitation department. Most people buy a small
>protein that is maximally soluble. Ubiquitin (zillions of 2- 3- 4- 5-D NMR
>experiments run on this with various forms of labeling) or lysozyme (it's
>cheap and you can dissolve a couple of hundred mgs per ml -- nice strong
>signals) or some such. Something like BPTI - 53 amino acids and stable like
>a rock might work. He doesn't say if he wants it labeled or not.
>
>
>There are some 18mer or so peptides which are alleged to be near 100%
>helical. You can't buy these. I think Earle Stellwagon and Neville
>Kallenbach published (separately) about these.
>
>
>Finally, the bee venom peptide, apamin, is available commercially (it might
>be expensive). It is 17 amino acids and has a couple of disulfide bonds
>which stabilize the helix.
>
>
>More information is needed to discern the requirements of this
>fellow. If he wants to set up experiments which will work with proteins
>later he might want to use something that has a rototational correlation
>time like a protein (a protein, for instance) instead of something tiny.
>
>
>Personal air-conditioning by pouring ice water down one's pants and/or
>margaritas down one's throat is too prevalent here to make liq. N2 a real
>threat.
>
>
>The last thing I remember before I woke up here was
The names I remember active in helical peptides were Bill DeGrado,
and Lynn Regan (now at Yale). (These are just the ones I met, ten years
ago. Many of their students would have their own labs by now.)
Melittin was another bee venom peptide which is probably commercially
available. David Eisenberg was active with it.
Note the ones you can't buy you can have synthesized ($10 per residue per 5
mg is $200/sample).
If you can't find a helix which is structured enough you might consider
zinc finger peptides which are also small, have a couple of turns of helix,
and are stapled into a well-defined structure by chelating a Zn or other
divalent cation. Jeremy Berg (Johns Hopkins) is one of many who has
published about them.
-- Roger
Received on Thu May 23 2002 - 17:43:29 MST