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Title: Characterization of proteins utilized in the desulfurization of petroleum products by matrix-assisted laser desorption ionization time-of-flight mass spectrometry

Journal Article · · Analytical Biochemistry
; ; ;  [1]; ;  [2]
  1. Texas A and M Univ., College Station, TX (United States). Dept. of Chemistry
  2. Energy Biosystems Corp., The Woodlands, TX (United States)

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI/TOF/MS) with delayed extraction is utilized in linear, reflected-ion and post-source decay (PSD) modes to directly characterize enzymes being developed for use in a petroleum desulfurization process. The DNA sequence for the genes isolated from Rhodococcus sp. strain IGTS8 that produce three of the four enzymes under study had been previously reported with a discrepancy in residue assignments for one of the enzymes, dsz-C. The use of proteolytic digests followed by MALDI/TOF/MS with delayed extraction in the reflected-ion mode provided sequence-specific information with mass accuracies exceeding 40 ppm over a range of masses and signal-to-noise values. Peptide mapping of >80% of the residues was accomplished for all four proteins. The use of PSD established the true sequence for dsz-C, resolving the discrepancy in the literature. A posttranslational loss of N-terminal methionine was observed for each of the four proteins in linear MALDI/MS and was reconfirmed by peptide mapping for three of the proteins.

Sponsoring Organization:
USDOE, Washington, DC (United States)
OSTI ID:
290173
Journal Information:
Analytical Biochemistry, Vol. 260, Issue 2; Other Information: PBD: 1 Jul 1998
Country of Publication:
United States
Language:
English