Abstract

It has been recognized for some time by us and other workers in the area of MALDI-MS that various components in a mixture do not enjoy the same ionization efficiency. This phenomenon frequently results in suppression of one or more components. Our objective is to characterize this phenomenon with model compounds in an effort to deal with it successfully if it cannot be overcome. Our procedure is to document the differential response of synthetic mixtures of peptides both free and chemically blocked according to amino acid composition and size as a function of matrix. Our preliminary observations are that the suppression during MALDI is not well correlated with molecular weight of the compound, but more likely correlatable with the hydrophilic character of the analyte. Our goal is to continue these assessments with a variety of matrices, with the goal of having a library of matrices available, some members of which may offer compensatory ionization efficiencies for those analytes that are expected to be suppressed in the initial matrix; this approach is expected to be especially effective in peptide mapping because the composition of a given fragment will be known and the extent to which it might be suppressed in particular matrices anticipated.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR000480-27
Application #
5220520
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
27
Fiscal Year
1996
Total Cost
Indirect Cost

  Publications

Peri, S P; Bhadti, V S; Somerville-Armstrong, K S et al. (1999) Affinity reagents for cross-linking hemoglobin: bis(phenoxycarbonylethyl)phosphinic acid (BPCEP) and bis(3-nitrophenoxycarbonylethyl)phosphinic acid (BNCEP). Hemoglobin 23:1-20
Chen, H M; Sood, R; Hosmane, R S (1999) An efficient, short synthesis and potent anti-hepatitis B viral activity of a novel ring-expanded purine nucleoside analogue containing a 5:7-fused, planar, aromatic, imidazo[4,5-e][1,3]diazepine ring system. Nucleosides Nucleotides 18:331-5
Bretner, M; Beckett, T D; Sood, R K et al. (1999) Substrate/inhibition studies of bacteriophage T7 RNA polymerase with the 5'-triphosphate derivative of a ring-expanded ('fat') nucleoside possessing potent antiviral and anticancer activities. Bioorg Med Chem 7:2931-6
Agasimundin, Y S; Mumper, M W; Hosmane, R S (1998) Inhibitors of glycogen phosphorylase b: synthesis, biochemical screening, and molecular modeling studies of novel analogues of hydantocidin. Bioorg Med Chem 6:911-23
Hosmane, R S; Peri, S P; Bhadti, V S et al. (1998) Bis[2-(4-carboxyphenoxy)carbonylethyl]phosphinic acid (BCCEP): a novel affinity reagent for the beta-cleft modification of human hemoglobin. Bioorg Med Chem 6:767-83
Rajappan, V P; Hosmane, R S (1998) Analogues of azepinomycin as inhibitors of guanase. Nucleosides Nucleotides 17:1141-51
Hosmane, R S; Hong, M (1997) How important is the N-3 sugar moiety in the tight-binding interaction of coformycin with adenosine deaminase? Biochem Biophys Res Commun 236:88-93
Lopez-Lara, I M; Orgambide, G; Dazzo, F B et al. (1993) Characterization and symbiotic importance of acidic extracellular polysaccharides of Rhizobium sp. strain GRH2 isolated from acacia nodules. J Bacteriol 175:2826-32
Watson, J T; Kayganich, K (1989) Novel sample preparation for analysis by electron capture negative ionization mass spectrometry. Biochem Soc Trans 17:254-7
Kassel, D B; Kayganich, K A; Watson, J T et al. (1988) Utility of ion source pretreatment with chlorine-containing compounds for enhanced performance in gas chromatography/negative ionization mass spectrometry. Anal Chem 60:911-7

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