All of the reagents you cite are acids, and of them, HCl (6N?) at 105 oC is
by far the strongest. Therefore, it will hydrolyze both proteins and DNA.
In the case of DNA, both the phosphodiester bonds and sugar/purine and
probably sugar/pyrimidine links will cleave. The resulting ribose
monophosphate esters may be stable--I'm not sure. HF will not have much
effect on the protein (it's used to deprotect peptides, after all), and
formic acid at 60 oC will probably cause partial hydrolysis of peptide
bonds, particularly at Asp.
If you use HCl you will end up with a mixture of sugars and amino acids,
which are likely react with each other to form, depending on how much of
each is present, brown "gunk"--the "browning" reaction. If you are doing
amino acid analysis, you will probably get erratic results because of this.
This is why one never wants to hydrolyze proteins in the presence of
carbohydrates. I believe you would get similar results in either the gas
phase or in solution.
Richard Laursen
-----------------------
>Dear ABRF's,
>
>I am working with a mixture of dna and protein and need to hydrolyse both
>consituents.
>In the past I have used HF(room temp) or formic acid(60 degrees C) for DNA
>hydrolysis and HCL(105 degrees C, 24 hrs) for protein hydrolysis. Will
>HF/formic acid hydrolyse protein and will HCL hydrolyse DNA or what would
>be an appropriate hydrolysis method?
>Also, how does gas phase hydrolysis of these compounds compare to leaving
>the compounds sit in the acid?
>My review of the literature has not enabled me to answer these questions.
>
>Any suggestions will be gratefully received.
>
>
>Thanking you,
>Kerryn Mason
>Senior Research Fellow
>Ray Williams Biomedical Mass Spectrometry Facility
>UNSW
>Sydney
>Australia
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>