Two species of entomogenous fungi were discovered infecting the invasive paper wasp during an ecological study on Farewell Spit, New Zealand. We sequenced two nuclear ribosomal RDNA genes, the internal transcribed spacer (ITS) and the small ribosomal subunit 18S, and one protein-coding gene, the translation elongation factor 1-alpha (). Combining sequence information with morphological examination, we identified these species as and .
View Article and Find Full Text PDFInfrared (IR) spectroscopy is increasingly being used to probe the secondary structure of proteins, especially for high-concentration samples and biopharmaceuticals in complex formulation vehicles. However, the small path lengths required for aqueous protein transmission experiments, due to high water absorbance in the amide I region of the spectrum, means that the path length is not accurately known, so only the shape of the band is ever considered. This throws away a dimension of information.
View Article and Find Full Text PDFDye-based protein determination assays are widely used to estimate protein concentration, however various reports suggest that the response is dependent on the composition and sequence of the protein, limiting confidence in the resulting concentration estimates. In this study a diverse set of model proteins representing various sizes of protein and covalent modifications, some typical of biopharmaceuticals have been used to assess the utility of dye-based protein concentration assays. The protein concentration assays (Bicinchoninic acid (BCA), Bradford, 3-(4-carboxybenzoyl)quinoline-2-carboxaldehyde (CBQCA), DC, Fluorescamine and Quant-i) were compared to the 'gold standard' assay, quantitative amino acid analysis (AAA).
View Article and Find Full Text PDFMycobacterium tuberculosis and Mycobacterium bovis, the causative agents of human and bovine tuberculosis, have been reported to express a range of surface and secreted glycoproteins, although only one of these has been subjected to detailed structural analysis. We describe the use of a genetic system, in conjunction with lectin binding, to characterize the points of attachment of carbohydrate moieties to the polypeptide backbone of a second mycobacterial glycoprotein, antigen MPB83 from M. bovis.
View Article and Find Full Text PDFTo identify the major outer surface proteins of Streptococcus agalactiae (group B streptococcus), a proteomic analysis was undertaken. An extract of the outer surface proteins was separated by two-dimensional electrophoresis. The visualized spots were identified through a combination of peptide sequencing and reverse genetic methodologies.
View Article and Find Full Text PDFThe lipopolysaccharide (LPS) from eight strains of Yersinia pestis which had been cultured at 28 degrees C appeared to be devoid of an O-antigen when analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. LPS isolated from three of these strains which had been cultured at 37 degrees C also appeared to be devoid of an O-antigen. When the LPS from Y.
View Article and Find Full Text PDFLipopolysaccharide (LPS) extracted from eight strains of Yersinia pestis, which had been cultured at 28 or 37 degrees C, reacted equally well, in Western blots, with four monoclonal antibodies generated against the LPS from a single strain of Y. pestis cultured at 28 degrees C. LPS was extracted and purified from Y.
View Article and Find Full Text PDFLouse-borne relapsing fever, caused by Borrelia recurrentis, provides one of the best documented examples of the causative role of tumor necrosis factor (TNF) in the pathology of severe infection in humans. We have identified the principal TNF-inducing factor of B. recurrentis as a variable major lipoprotein (Vmp).
View Article and Find Full Text PDFHuman secretory component has seven putative sites for N-linked glycosylation. From tryptic and Glu-C digests we have isolated peptides encompassing asparagines 65, 72, 117, 168, 403, 451 and 481. Analysis by on line HPLC-electrospray mass spectrometry indicated that these residues were fully glycosylated and that the major carbohydrate moieties were far less diversified in composition than expected.
View Article and Find Full Text PDFN-Type glycans containing phosphorylcholine (PC-glycans), unusual structures found in the important human pathogens filarial nematodes, represent a novel target for chemotherapy. Previous work in our laboratories produced compositional information on the PC-glycan of ES-62, a secreted protein of the rodent parasite Acanthocheilonema viteae. In particular, we established using fast atom bombardment mass spectrometry (MS) analysis that PC was attached to a glycan with a trimannosyl core, with and without core fucosylation, carrying between one and four additional N-acetylglucosamine residues.
View Article and Find Full Text PDFThe important role of furin in the proteolytic activation of many pathogenic molecules has made this endoprotease a target for the development of potent and selective antiproteolytic agents. Here, we demonstrate the utility of the protein-based inhibitor alpha1-antitrypsin Portland (alpha1-PDX) as an antipathogenic agent that can be used prophylactically to block furin-dependent cell killing by Pseudomonas exotoxin A. Biochemical analysis of the specificity of a bacterially expressed His- and FLAG-tagged alpha1-PDX (alpha1-PDX/hf) revealed the selectivity of the alpha1-PDX/hf reactive site loop for furin (Ki, 600 pM) but not for other proprotein convertase family members or other unrelated endoproteases.
View Article and Find Full Text PDFThe major N-linked carbohydrate structures were determined for recombinant human plasma lecithin:cholesterol acyltransferase (LCAT). The analysis of the structure of oligosaccharides by fast atom bombardment mass spectrometry (FAB-MS) and linkage analysis was preceded by reduction and carboxymethylation of the intact glycoproteins and digestion with trypsin and proline specific endopeptidase. The N-glycans were subsequently released from the glycopeptides by PNGase F digestion and the oligosaccharides were separated using a C18 Sep-pak cartridge.
View Article and Find Full Text PDFThe main objective of this work was to unequivocally determine the C-terminal sequence of human milk free secretory component (SC). It was found to end at arginine-585, i.e.
View Article and Find Full Text PDFTrideuteriomethylated and methylated derivatives of the capsular polysaccharide of Escherichia coli K57 were partially cleaved by Et3SiH, using Me3SiOSO2 Me and Me3SiOSO2CF3 as catalysts, to produce oligosaccharide-anhydroalditols. The structures of the trideuteriomethylated trisaccharide- and tetrasaccharide-anhydroalditols isolated were established by FABMS and NMR spectroscopy. Although conditions for the selective production of the tetrasaccharide-anhydroalditol could not be established, oligosaccharide-anhydroalditols were isolated in sufficiently high yield to make this an attractive approach for the structural elucidation of the repeating units of bacterial polysaccharides.
View Article and Find Full Text PDFThe larval stage of the intestinal nematode, Trichinella spiralis, secretes and displays on its cuticle a number of antigenically cross-reactive glycoproteins. These so-called TSL-1 antigens induce a powerful antibody response in parasitized animals. In rats, anti-TSL-1 antibodies mediate a protective immunity that expels invading larvae from the intestine.
View Article and Find Full Text PDFWe have investigated the role of glycans on Trichinella spiralis antigens in recognition by rat monoclonal antibodies (mAbs) which protect rat pups against challenge with the parasite. In pups born to infected dams or pups passively immunized with mAbs, antibodies eliminate a challenge dose from the intestine within hours ('rapid expulsion'). Because such dramatic protection can be afforded by mAbs, we have sought to characterize the parasite antigens they target.
View Article and Find Full Text PDFThe N-linked oligosaccharides of frog (Rana pipiens) rhodopsin were analysed by sequential exoglycosidase digestion and gel filtration chromatography, following reductive tritiation. In addition, selected tryptic glycopeptides obtained from frog retinal rod outer segment membranes were examined by electrospray mass spectrometry (ES-MS), fast atom bombardment mass spectrometry (FAB-MS), amino acid sequence and composition analysis, and carbohydrate composition analysis. The amino acid sequence data demonstrated that the glycopeptides were derived from rhodopsin and confirmed the presence of two N-glycosylation sites, at residues Asn2 and Asn15.
View Article and Find Full Text PDFCarbohydrate analysis is an active field that is expanding rapidly. Hundreds of new structures are reported each year and methods for screening glycopolymers for known structures are now becoming accessible to the nonspecialist. Detailed structure analysis of recombinant glycoproteins has become relatively routine in specialist laboratories.
View Article and Find Full Text PDFA unique form of nucleoplasmic and cytoplasmic protein glycosylation, O-linked GlcNAc, has previously been detected, using Gal transferase labeling techniques, on a myriad of proteins (for review see Hart, G. W., Haltiwanger, R.
View Article and Find Full Text PDFThe structure of the capsular antigen from Escherichia coli O8:K46:H30 was elucidated by methylation analysis and 1D and 2D 1H- and 13C-NMR spectroscopy, and by methylation analysis, 1D- and 2D-NMR spectroscopy, and FABMS of the oligosaccharide-alditol obtained after dephosphorylation of the polymer with aqueous hydrofluoric acid. The capsular polymer is of the teichoic acid type and has the following repeating unit. [Formula: see text]
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