General Method for MALDI-MS Analysis of Proteins and Peptides.

INTRODUCTIONFor MALDI-TOF-MS analysis of proteins and peptides, samples are cocrystallized with an excess of organic matrix that absorbs at a specific wavelength (usually, UV(337nm)). Typically, sinapinic acid (SA) is the matrix of choice for large proteins, whereas α-cyano-4-hydroxy-cinnamic acid (HCCA) is the preferred matrix for peptide mapping. Following a short laser pulse, analytes are protonated and desorbed into the gas phase, and their m/z values are determined in a TOF mass analyzer.

Enzymic, phylogenetic, and structural characterization of the unusual papain-like protease domain of Plasmodium falciparum SERA5.

Serine repeat antigen 5 (SERA5) is an abundant antigen of the human malaria parasite Plasmodium falciparum and is the most strongly expressed member of the nine-gene SERA family. It appears to be essential for the maintenance of the erythrocytic cycle, unlike a number of other members of this family, and has been implicated in parasite egress and/or erythrocyte invasion. All SERA proteins possess a central domain that has homology to papain except in the case of SERA5 (and some other SERAs), where the active site cysteine has been replaced with a serine.

CHOMPER: a bioinformatic tool for rapid validation of tandem mass spectrometry search results associated with high-throughput proteomic strategies.

Current efforts aimed at developing high-throughput proteomics focus on increasing the speed of protein identification. Although improvements in sample separation, enrichment, automated handling, mass spectrometric analysis, as well as data reduction and database interrogation strategies have done much to increase the quality, quantity and efficiency of data collection, significant bottlenecks still exist. Various separation techniques have been coupled with tandem mass spectrometric (MS/MS) approaches to allow a quicker analysis of complex mixtures of proteins, especially where a high number of unambiguous protein identifications are the exception, rather than the rule.

Mixed lineage kinase 2 interacts with clathrin and influences clathrin-coated vesicle trafficking.

Mixed lineage kinase 2 (MLK2) is a protein kinase that signals in the stress-activated Jun N-terminal kinase signal transduction pathway. We used immunoprecipitation and mass spectrometric analysis to identify MLK2-binding proteins in cell lines with inducible expression of green fluorescent protein-tagged MLK2. Here we report the identification of clathrin as a binding partner for MLK2 in both cultured cells and mammalian brain.