@article {1215, title = {Identification of 2D-gel proteins: a comparison of MALDI/TOF peptide mass mapping to mu LC-ESI tandem mass spectrometry.}, journal = {J Am Soc Mass Spectrom}, volume = {14}, year = {2003}, month = {2003 Sep}, pages = {957-70}, abstract = {

A comparative analysis of protein identification for a total of 162 protein spots separated by two-dimensional gel electrophoresis from two fully sequenced archaea, Methanococcus jannaschii and Pyrococcus furiosus, using MALDI-TOF peptide mass mapping (PMM) and mu LC-MS/MS is presented. 100\% of the gel spots analyzed were successfully matched to the predicted proteins in the two corresponding open reading frame databases by mu LC-MS/MS while 97\% of them were identified by MALDI-TOF PMM. The high success rate from the PMM resulted from sample desalting/concentrating with ZipTip(C18) and optimization of several PMM search parameters including a 25 ppm average mass tolerance and the application of two different protein molecular weight search windows. By using this strategy, low-molecular weight (<23 kDa) proteins could be identified unambiguously with less than 5 peptide matches. Nine percent of spots were identified as containing multiple proteins. By using mu LC-MS/MS, 50\% of the spots analyzed were identified as containing multiple proteins. mu LC-MS/MS demonstrated better protein sequence coverage than MALDI-TOF PMM over the entire mass range of proteins identified. MALDI-TOF and PMM produced unique peptide molecular weight matches that were not identified by mu LC-MS/MS. By incorporating amino acid sequence modifications into database searches, combined sequence coverage obtained from these two complimentary ionization methods exceeded 50\% for approximately 70\% of the 162 spots analyzed. This improved sequence coverage in combination with enzymatic digestions of different specificity is proposed as a method for analysis of post-translational modification from 2D-gel separated proteins.

}, keywords = {Amino Acid Sequence, Chromatography, Liquid, Databases, Protein, Electrophoresis, Gel, Two-Dimensional, Methanococcus, Molecular Sequence Data, Molecular Weight, Peptide Mapping, Proteins, Pyrococcus furiosus, Sensitivity and Specificity, Software, Spectrometry, Mass, Electrospray Ionization, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Trypsin}, issn = {1044-0305}, author = {Lim, Hanjo and Eng, Jimmy and Yates, John R and Tollaksen, Sandra L and Giometti, Carol S and Holden, James F and Adams, Michael W W and Reich, Claudia I and Olsen, Gary J and Hays, Lara G} } @article {1216, title = {Microbe-metal interactions in marine hydrothermal environments.}, journal = {Curr Opin Chem Biol}, volume = {7}, year = {2003}, month = {2003 Apr}, pages = {160-5}, abstract = {

Marine hydrothermal microorganisms respond rapidly to changes in the concentrations and availability of metals within their environment. Hyperthermophilic archaea appear to possess novel mechanisms for metal detoxification, dissimilatory metal reduction and metal assimilation that may be absent in their mesophilic and bacterial counterparts. For example, tungsten was found in high concentrations in a hydrothermal sulfide deposit where hyperthermophiles were also most abundant, consistent with the unique requirement of these organisms for this element. Furthermore, newly isolated genera of iron-reducing hyperthermophiles expand the scope of carbon cycling in hydrothermal environments. The advent of genome sequences and new molecular techniques will facilitate our further understanding of microbe-mineral interactions in these environments.

}, keywords = {Archaea, Bacteria, Environment, Marine Biology, Metals, Seawater, Temperature}, issn = {1367-5931}, author = {Holden, James F and Adams, Michael W W} }