@article {1212,
	title = {Characterization of malate dehydrogenase from the hyperthermophilic archaeon Pyrobaculum islandicum.},
	journal = {Extremophiles},
	volume = {11},
	year = {2007},
	month = {2007 Sep},
	pages = {741-6},
	abstract = {<p>Native and recombinant malate dehydrogenase (MDH) was characterized from the hyperthermophilic, facultatively autotrophic archaeon Pyrobaculum islandicum. The enzyme is a homotetramer with a subunit mass of 33 kDa. The activity kinetics of the native and recombinant proteins are the same. The apparent K ( m ) values of the recombinant protein for oxaloacetate (OAA) and NADH (at 80 degrees C and pH 8.0) were 15 and 86 microM, respectively, with specific activity as high as 470 U mg(-1). Activity decreased more than 90\% when NADPH was used. The catalytic efficiency of OAA reduction by P. islandicum MDH using NADH was significantly higher than that reported for any other archaeal MDH. Unlike other archaeal MDHs, specific activity of the P. islandicum MDH back-reaction also decreased more than 90\% when malate and NAD(+) were used as substrates and was not detected with NADP(+). A phylogenetic tree of 31 archaeal MDHs shows that they fall into 5 distinct groups separated largely along taxonomic lines suggesting minimal lateral mdh transfer between Archaea.</p>},
	keywords = {Citric Acid Cycle, Hydrogen-Ion Concentration, Kinetics, Malate Dehydrogenase, Malates, Molecular Weight, NAD, NADP, Oxaloacetic Acid, Phylogeny, Protein Conformation, Protein Subunits, Pyrobaculum, Recombinant Proteins, Sequence Analysis, Protein, Substrate Specificity, Temperature},
	issn = {1431-0651},
	doi = {10.1007/s00792-007-0081-2},
	author = {Yennaco, Lynda J and Hu, Yajing and Holden, James F}
}
@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 = {<p>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.</p>},
	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}
}
