Abstract

Although no crystal structure of mammalian hexokinase is available, extensive work on the characterization of hexokinase has been carried out. Questions remain on the number and position of disulfide bonds present in this enzyme containing 27 cysteines. Our goal is to provide this information using MALDI-MS. Technology is now available to address structural questions on proteins of this size (more than 900 residues). The first step in this project is to perform standard proteolytic digestions of the enzyme and use MALDI to determine the masses of the digestion products that can be desorbed and ionized in the experiment. The complete digestion is first being analyzed as a single, complex mixture. Next, a simple HPLC fractionation will be performed to determine whether the full set of digestion products can be detected in a single experiment, or if some components suppress the detection of others. We will evaluate whether disulfide bond cleavage and scrambling occurs in the digestion or ionization process. Once the situation has been defined, experimental modifications can be designed to give the desired structural information.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR000480-27
Application #
5220513
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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