Targeted proteomics approaches are of value for deep and accurate quantification of protein abundance. Extending such methods to quantify large numbers of proteins requires the construction of predefined targeted assays. We developed a targeted proteomics platform-in vitro proteome-assisted multiple reaction monitoring (MRM) for protein absolute quantification (iMPAQT)-by using >18,000 human recombinant proteins, thus enabling protein absolute quantification on a genome-wide scale. Our platform comprises experimentally confirmed MRM assays of mass tag (mTRAQ)-labeled peptides to allow for rapid and straightforward measurement of the absolute abundance of predefined sets of proteins by mass spectrometry. We applied iMPAQT to delineate the quantitative metabolic landscape of normal and transformed human fibroblasts. Oncogenic transformation gave rise to relatively small but global changes in metabolic pathways resulting in aerobic glycolysis (Warburg effect) and increased rates of macromolecule synthesis. iMPAQT should facilitate quantitative biology studies based on protein abundance measurements.
The crystal structure of the terminal component of the cumene dioxygenase multicomponent enzyme system of Pseudomonas fluorescens IP01 (CumDO) was determined at a resolution of 2.2 Å by means of molecular replacement by using the crystal structure of the terminal oxygenase component of naphthalene dioxygenase from Pseudomonas sp. strain NCIB 9816-4 (NphDO). The ligation of the two catalytic centers of CumDO (i.e., the nonheme iron and Rieske [2Fe-2S] centers) and the bridging between them in neighboring catalytic subunits by hydrogen bonds through a single amino acid residue, Asp231, are similar to those of NphDO. An unidentified external ligand, possibly dioxygen, was bound at the active site nonheme iron. The entrance to the active site of CumDO is different from the entrance to the active site of NphDO, as the two loops forming the lid exhibit great deviation. On the basis of the complex structure of NphDO, a biphenyl substrate was modeled in the substrate-binding pocket of CumDO. The residues surrounding the modeled biphenyl molecule include residues that have already been shown to be important for its substrate specificity by a number of engineering studies of biphenyl dioxygenases.Aromatic hydrocarbons are common contaminants of soil and groundwater (18). One of the most attractive means of removal of these compounds from the environment is the use of microorganisms (34). Dihydroxylation of the aromatic ring by a bacterial aromatic hydrocarbon dioxygenase is a prerequisite for subsequent oxidation of the aromatic nucleus by a ring fission dioxygenase (6). Aromatic hydrocarbon dioxygenases belong to a large family named the Rieske nonheme iron oxygenases (11). Werlen et al. delineated four dioxygenase subfamilies in this large family (the toluene/biphenyl, naphthalene, benzoate, and phthalate subfamilies) based on sequence alignment of the catalytic components (␣ subunits) (37). The toluene/biphenyl subfamily includes enzymes for the degradation of toluene, benzene, cumene (isopropylbenzene), biphenyl, and polychlorinated biphenyls (PCBs). The naphthalene subfamily consists of enzymes for the degradation of naphthalene and phenanthrene. The Rieske dioxygenases involved in bacterial hydrocarbon degradation comprise multicomponent enzyme systems (36) in which reduced pyridine nucleotide is used as the initial source of two electrons for dioxygen activation. The electrons pass through a flavin cofactor and Rieske [2Fe-2S] centers into the mononuclear iron center of the terminal Rieske nonheme iron dioxygenase component.The crystal structure of the terminal oxygenase component of naphthalene dioxygenase from Pseudomonas sp. NCIB 9816-4 (NphDO) has been reported previously (4,15,17), and the structure-function relationship of this enzyme has been well studied (28). NphDO is an ␣ 3  3 hexamer, and each ␣ subunit contains a Rieske [2Fe-2S] cluster and nonheme iron coordinated by His208, His213, and Asp362. The active site iron center of one of the ␣ subunits is directly connected by hydrogen bonds through a singl...
a b s t r a c tPigmentation in avian eggshells appears to be associated with shell strength, temperature regulation, and camouflage. The pigments found in eggshells are mainly porphyrins, which have been utilized therapeutically as photosensitizers. Here, we examined the photoinactivation of gram-positive (Staphylococcus aureus, Bacillus cereus) and gram-negative bacteria (Escherichia coli, Salmonella enteritidis) by hen eggshells and their pigments. The results indicated that eggshells have a lightdependent antimicrobial activity against gram-positive, but not gram-negative, bacteria. Our results indicate the possibility that the natural pigments used therapeutically have evolved in nature as a defence system.
To develop sero-diagnostic markers for lung cancer, we generated monoclonal antibodies using lung adenocarcinoma (AC)-derived A549 cells as antigens by employing the random immunization method. Hybridoma supernatants were immunohistochemically screened for antibodies with AMeX-fixed and paraffin-embedded A549 cell preparations. Positive clones were monocloned twice through limiting dilutions. From the obtained monoclonal antibodies, one designated as KU-Lad-001 was recognized as calnexin (CANX) based on immunoprecipitation and MADLI TOF/TOF-MS analysis. To evaluate the utility of this antibody as a sero-diagnostic marker for lung cancer, we performed reverse-phase protein array analysis with samples of 195 lung cancer patients and 100 healthy controls. The CANX expression levels were significantly higher in lung cancer patients than in healthy controls (P<0.0001), and the area under the curve of ROC was 0.980, with 96.9% specificity and 99.0% sensitivity. Furthermore, since CANX was also detected in stage I disease, the serum CANX levels should be applicable markers discriminating lung cancer patients from healthy controls and possibly used in the detection of early lung cancer. To our knowledge, the present results provide evidence that CANX may be a novel sero-diagnostic marker for lung cancer.
Our aim was to develop a serodiagnostic marker for lung cancer. Monoclonal antibodies were generated, and one antibody designated as KU-Lu-1, recognizing cytoskeleton-associated protein 4 (CKAP4), was studied further. To evaluate the utility of KU-Lu-1 antibody as a serodiagnostic marker for lung cancer, reverse-phase protein array analysis was performed with sera of 271 lung cancer patients and 100 healthy controls. CKAP4 was detected in lung cancer cells and tissues, and its secretion into the culture supernatant was also confirmed. The serum CKAP4 levels of lung cancer patients were significantly higher than those of healthy controls (P < 0.0001), and the area under the curve of receiver-operating characteristic curve analysis was 0.890, with 81.1% sensitivity and 86.0% specificity. Furthermore, the serum CKAP4 levels were also higher in patients with stage I adenocarcinoma or squamous cell carcinoma than in healthy controls (P < 0.0001). Serum CKAP4 levels may differentiate lung cancer patients from healthy controls, and they may be detected early even in stage I non-small cell lung cancer. Serum CKAP4 levels were also significantly higher in lung cancer patients than in healthy controls in the validation set (P < 0.0001). The present results provide evidence that CKAP4 may be a novel early serodiagnostic marker for lung cancer.
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