Characterization of Proteins Utilized in the Desulfurization of Petroleum Products by Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry Academic Article uri icon

abstract

  • 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.

author list (cited authors)

  • Wolf, B. P., Sumner, L. W., Shields, S. J., Nielsen, K., Gray, K. A., & Russell, D. H.

citation count

  • 4

publication date

  • July 1998