Partial characterization of chitin degrading enzymes from two euphausiids,Euphausia superba and Meganyctiphanes norvegica

Summary Chitinase and N-acetyl--D-glucosaminidase have been demonstrated in Meganyctiphanes norvegica and in Euphausia superba and partly characterized. The enzymes from both species have broad pH-optima (maxima around pH 5.0) and temperature optima between 40 and 50°C. The enzymes are relatively stable; even at about 45°C half of the enzyme activity is retained after 30 min incubation. The presence of fluoride does not affeet enzymatic activity. Chitinase activity appears in three different molecular masses, N-acetyl--D-glucosaminidases in two different forms. pH and temperature optima, thermal stability and kinetic properties of the two enzymes are strikingly similar in the polar E. superba versus the boreal euphausiid M. norvegica. Enzyme activity in the lower temperature range is still high, whereas activation energies are low in both euphausiids. This suggests a functional adaptation to a low temperature range in seawater.     

Novel Potential Interacting Partners of Fibronectin in Spontaneous Animal Model of Interstitial Cystitis

Feline idiopathic cystitis (FIC) is the only spontaneous animal model for human interstitial cystitis (IC), as both possess a distinctive chronical and relapsing character. Underlying pathomechanisms of both diseases are not clearly established yet. We recently detected increased urine fibronectin levels in FIC cases. The purpose of this study was to gain further insight into the pathogenesis by assessing interacting partners of fibronectin in urine of FIC affected cats. Several candidate proteins were identified via immunoprecipitation and mass spectrometry. Considerable changes in FIC conditions compared to physiological expression of co-purified proteins were detected by Western blot and immunohistochemistry. Compared to controls, complement C4a and thioredoxin were present in higher levels in urine of FIC patients whereas loss of signal intensity was detected in FIC affected tissue. Galectin-7 was exclusively detected in urine of FIC cats, pointing to an important role of this molecule in FIC pathogenesis. Moderate physiological signal intensity of galectin-7 in transitional epithelium shifted to distinct expression in transitional epithelium under pathophysiological conditions. I-FABP expression was reduced in urine and urinary bladder tissue of FIC cats. Additionally, transduction molecules of thioredoxin, NF-κB p65 and p38 MAPK, were examined. In FIC affected tissue, colocalization of thioredoxin and NF-κB p65 could be demonstrated compared to absent coexpression of thioredoxin and p38 MAPK. These considerable changes in expression level and pattern point to an important role for co-purified proteins of fibronectin and thioredoxin-regulated signal transduction pathways in FIC pathogenesis. These results could provide a promising starting point for novel therapeutic approaches in the future.     

Neuropeptide Y receptors: ligand binding and trafficking suggest novel approaches in drug development

NPY, PYY and PP constitute the so‐called NPY hormone family, which exert its biological functions in humans through YRs (Y₁, Y₂, Y₄ and Y₅). Systematic modulation of YR function became important as this multireceptor/multiligand system is known to mediate various essential physiological key functions and is involved in a variety of major human diseases such as epilepsy, obesity and cancer. As several YRs have been found to be overexpressed on different types of malignant tumors they emerge as promising target in modern drug development. Here, we summarize the current understanding of YRs function and the molecular mechanisms of ligand binding and trafficking. We further address recent advances in YR‐based drug design, the development of promising future drug candidates and novel approaches in YR‐targeted tumor diagnostics and therapy opportunities. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.     

Biotransformation of Paclitaxel (Taxol) by the Cell Suspension Cultures of Rauwolfia serpentina

The biotransformation of paclitaxel (TaxolⓇ) by the cell suspension cultures of Rauwolfia serpentina (L.) Benth. et Kurz. were investigated. Three Paclitaxel-based intracellular metabolites were detected from the cell filter cake and were, by high field ¹H-NMR and MS data, identified as 10-deacetyltaxol, baccatin Ⅲ, and 10-deacetylbaccatin Ⅲ. No glucosidated or hydroxylated derivatives were checked out in this incubation experiment.     

Biofilm research using calorimetry – a marriage made in heaven?

Aggregated bacteria growing on a surface, so-called biofilms, play an important role in technical processes like wastewater treatment, bioremediation, or bioprocessing. In contrast, problems arise when biofilm growth results in undesired processes that may cause huge financial losses, e.g., clogged pipes, microbially influenced corrosion or pathogenic contamination. For observation purposes and to develop efficient control strategies, real-time monitoring tools for biofilms are required. Among the large variety of tools used in biofilm research, calorimetry is rarely applied, even though many characteristics qualify it for biofilm investigation and monitoring. Calorimetric measurements are non-invasive and non-destructive, and can be applied to nearly any kind of samples (including heterogeneous or turbid solutions) without the need of special sample preparation. Online and real-time data acquisition reduces the labor and facilitates high-throughput measurements. The following article is meant to introduce and promote calorimetry as a future tool in biofilm research. It attempts an assessment of common, existent monitoring tools and specifically addresses the potential of calorimetry in this field.