Production of ochratoxin a,citrinin, and ergosterol byPenicillium viridicatum in autoclaved and non-autoclaved wheat at low temperature

Wheat (moisture content: 26%) was autoclaved or left untreated, inoculated with conidia ofPenicillium viridicatum and stored at 10°C. The fungus grew on both substrates and was the dominant mould on the non-autoclaved grain. Autoclaving resulted in an earlier onset of ergosterol, ochratoxin A, and citrinin production due to accelerated mould growth. Yield of ochratoxin A increased while citrinin slightly decreased in autoclaved wheat.     

Expression of epidermal growth factor receptor and associated glycoprotein on cultured human brain tumor cells

The expression of epidermal growth factor (EGF-R) in normal glial and glioma cells grown in culture was examined by using several independent assays. Immunoprecipitation with the monoclonal antibody R1 of extracts from metabolically labeled glial and glioma cells revealed a protein of Mr approximately 170,000, with a migration in sodium dodecyl sulfate-polyacrylamide gels identical to the EGR-R of A431 epidermal carcinoma cells. Furthermore, in the majority of glioma extracts, a protein of Mr approximately 190,000 was specifically immunoprecipitated by this antibody. Similar results were obtained by immunoblotting with a second antibody directed against a synthetic peptide in the sequence of the v-erb-B oncogene. In cell lines expressing both proteins, each was specifically phosphorylated on tyrosine in immune complex kinase assays. The majority of glioma cells bound between 40,000 to 80,000 125I-labeled epidermal growth factor molecules per cell. These results suggest that the expression of EGF-R is common in cultured human glioma cells. In addition, a structurally related protein, is expressed in some of these cells.     

Über die Veränderung der chemischen Zusammensetzung vonScenedesmus obliquus bei synchroner Kultur im Licht-Dunkel-Wechsel

Ohne ZusammenfassungMit 10 Textabbildungen     

Botryorhodines A-D, antifungal and cytotoxic depsidones from Botryosphaeria rhodina, an endophyte of the medicinal plant Bidens pilosa

An endophytic fungus (Botryosphaeria rhodina) was isolated from the stems of the medicinal plant Bidens pilosa (Asteraceae) that is known for its anti-inflammatory, antiseptic and antifungal effects. The ethyl acetate extract of the fungal isolate exhibits significant antifungal activity as well as potent cytotoxic and antiproliferative effects against several cancer cell lines. Activity-guided fractionation resulted in the isolation of a complex of four depsidones, botryorhodines A-D and the auxin indole carboxylic acid. Botryorhodine A and B show moderate to weak cytotoxic activities against HeLa cell lines with a CC₅₀ of 96.97 μM and 36.41 μM, respectively. In addition, they also show antifungal activity against a range of pathogenic fungi such as Aspergillus terreus (MIC 26.03 μM for botryorhodine A and 49.70 μM for B) and the plant pathogen Fusarium oxysporum (MIC 191.60 μM for botryorhodine A and 238.80 μM for B). A potential role of the endophyte in modulating fungal populations living within or attacking the host plant is discussed.     

The COMPASS family of H3K4 methylases in Drosophila

Methylation of histone H3 lysine 4 (H3K4) in Saccharomyces cerevisiae is implemented by Set1/COMPASS, which was originally purified based on the similarity of yeast Set1 to human MLL1 and Drosophila melanogaster Trithorax (Trx). While humans have six COMPASS family members, Drosophila possesses a representative of the three subclasses within COMPASS-like complexes: dSet1 (human SET1A/SET1B), Trx (human MLL1/2), and Trr (human MLL3/4). Here, we report the biochemical purification and molecular characterization of the Drosophila COMPASS family. We observed a one-to-one similarity in subunit composition with their mammalian counterparts, with the exception of LPT (lost plant homeodomains [PHDs] of Trr), which copurifies with the Trr complex. LPT is a previously uncharacterized protein that is homologous to the multiple PHD fingers found in the N-terminal regions of mammalian MLL3/4 but not Drosophila Trr, indicating that Trr and LPT constitute a split gene of an MLL3/4 ancestor. Our study demonstrates that all three complexes in Drosophila are H3K4 methyltransferases; however, dSet1/COMPASS is the major monoubiquitination-dependent H3K4 di- and trimethylase in Drosophila. Taken together, this study provides a springboard for the functional dissection of the COMPASS family members and their role in the regulation of histone H3K4 methylation throughout development in Drosophila.     

A colloidal silver staining--destaining method for precise assignment of immunoreactive spots in two-dimensional protein patterns

The characterization of protein expression patterns by two-dimensional gel electrophoresis depends on efficient and reliable identification strategies for target spots. In addition to sophisticated techniques, such as microsequencing and peptide mass spectrometry, immunodetection of membrane-immobilized proteins is a valuable method with which to identify the corresponding spots for a given set of candidate proteins. To precisely assign immunoreactive spots, this approach requires specific immunodetection and staining of total protein to be performed on the same membrane. Here, we describe a highly sensitive, colloidal silver-based method for the assignment of immunoreactive spots in two-dimensional protein patterns. This simple and rapid procedure involves a destaining step after staining of nitrocellulose-bound proteins with colloidal silver. We show that destaining of proteins is a prerequisite for subsequent immunodetection using enhanced chemiluminescence. Several types of antibodies were successfully employed for antigen detection after the staining-destaining procedure. Our results demonstrate that the colloidal silver-based method is generally applicable for the unambiguous identification of candidate proteins in complex two-dimensional patterns.