Gary's suggestions are excellent. we have done lots of work with DNA and
DNA peptide interaction by MALDI. One paper has been published and the
second will be submitted shortly. The reference is
S. Lin, R. Cotter and A. Woods "Detection of Non-Covalent Interaction of
Single and Double stranded DNA with peptides by MALDI-TOF". Proteins:
Structure, Function and Genetics Suppl. 2:12-21 (1998).
If you have any question please e-mail me.
Amina
Amina S. Woods, Ph.D.
Johns Hopkins School of Medicine
725 N Wolfe street, Baltimore, MD 21205
Biophysics Building Rm. B7
Tel: (410) 614-4981, Fax: (410) 955-3420
e-mail: awoods@jhmi.edu
----------
From: ABRF[SMTP:abrf@its.caltech.edu]
Sent: Wednesday, June 16, 1999 11:39 AM
To: Recipients of ABRF List
Subject: Re: MS
At 2:14 AM -0700 6/16/99, Ulf Hellman wrote:
>Dear MALDI users!
>Can anyone please suggest a robust procedure for MALDI analysis of
>oligonucleotides and similar components. Type of matrix, type of modes
>(lin/refl, pos/neg, etc) in the instrument, sample pretreatment, solvents
>and whatever might be relevant? Realistic concentration of analyte?
>Thanks in advance. /Ulf
>******************************************************
>Ulf,
6-aza-2-thiothymine: Lecchi, P. et al. Nucl. Acids Res. 23, 1276-1277
(1995)
3-hydroxypicolinic acid: Talbo, G. and Mann, M. Rapid Commun. Mass Spectr.
10, 100-103 (1996)
2,4,6-trihydroxyacetophenone: Pieles et al. Nucl. Acids Res. 21, 3191-3196
(1993).
2,3,4-trihydroxyacetophenone: Zhu et al. Rapid Commun. Mass Spectr. 10,
383-388 (1996).
Each of the above matrices has its own formulation and you will either have
to get the original papers, or send me your FAX No. and I will FAX our
worksheet on "how to do it".
I have found 3-HPA is good for oligos, 5 kDa and larger. The matrix we have
has sodium and potassium present which gives some headaches.
6-aza is good for oligos up to 5 kDa and shows little adduction of metal
ions or matrix. You can pretreat the sample with a few beads of cation
exchanger which you make as the ammonium form, or use some other means of
rigourously desalting the oligos. We run both reflector and linear DE modes
in negative ion mode, 20 KV. Your oligo should be from several hundred
femtomoles to about 1 pmole depending on MW and purity.
Best regards,
Gary
Gary M. Hathaway
Director, Protein Analytical Lab
Caltech, 139-74
400 S. Wilson Ave.
Pasadena, CA 91125
hathaway@cco.caltech.edu