Search PubMed⌕ Search

Biomedical subjects

J Salnikow

Publications and source records attributed to J Salnikow.

35 records · Page 2Linked to original sources

A new polyene with antimycotic activity produced by a streptomycete from the rhizosphere of an indoor plant.

From the rhizosphere of a potted Sanseviera trifasciata, a Streptomyces griseus strain with a broad antifungal activity was isolated; in the soil of this plant, a sole hyphomycete, Aspergillus niger, was found in pure culture at 37 degrees C. This streptomycete produced a polyene, belonging to the pentaene group. It was found to inhibit, in vitro, the growth of all the 123 strains tested; the strains belonging to the genera Aspergillus, Cryptococcus, Candida, Trichophyton, Epidermophyton, Microsporum, Penicillium and Mucor. An antimycotic activity of this substance was also found to be present after i.v. administration to white mice infected with Cr. neoformans. Toxicological tests will have to show if this polyene could be considered as a candidate antimycotic drug. The soil of potted indoor plants is discussed as a possible habitat for streptomycetes with defined antifungal activities.

Animals↗

Biosynthesis of carnosine and related peptides by glial cells in primary culture.

Synthesis of carnosine (beta-alanylhistidine) and related peptides by glial cells in primary culture could be demonstrated. After incubation with [3H]beta-alanine, the radiolabeled dipeptides could be isolated from the cell extract and the culture medium. With gamma-amino[3H]butyric acid, however, rapid degradation of the tracer without significant synthesis of homocarnosine (gamma-aminobutyrylhistidine) was observed. Aminooxyacetic acid, a known inhibitor of gamma-aminobutyryl:alpha-ketoglutarate aminotransferase, inhibits the degradation of gamma-amino[3H]butyric acid very strongly and of [3H]beta-alanine partially. After preincubation of the cells with this inhibitor, incorporation of gamma-amino[3H]butyric acid into homocarnosine and related peptides could be demonstrated.

Alanine↗

A two-dimensional electrophoresis database of rat heart proteins.

More than 3000 myocardial protein species of Wistar Kyoto rat, an important animal model, were separated by high-resolution two-dimensional gel electrophoresis (2-DE) and characterized in terms of isoelectric point (pI) and molecular mass (Mr). Currently, the 2-DE database contains 64 identified proteins; forty-three were identified by peptide mass fingerprinting (PMF) using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), nine by exclusive comparison with other 2-DE heart protein databases, and in only 12 cases of 60 attempts N-terminal sequencing was successful. We used the Make2ddb software package downloaded from the ExPASy server for the construction of a rat myocardial 2-DE database. The Make2ddb package simplifies the creation of a new 2-DE database if the Melanie II software and a Sun workstation under Solaris are available. Our 2-DE database of rat heart proteins can be accessed at URL http://gelmatching.inf.fu-berlin.de/pleiss/2d.

Animals↗

Competition of pyridoxal 5'-phosphate with ribulose 1,5-bisphosphate and effector sugar phosphates at the reaction centers of the spinach ribulose 1,5-bisphosphate carboxylase/oxygenase.

The stimulation of the carboxylase reaction by effectors of ribulose 1,5-bisphosphate carboxylase/oxygenase displays higher sensitivity towards pyridoxal 5'-pyridoxal 5'-phosphate inhibition than the catalytical process itself. Pyridoxal 5'-phosphate binding to the enzyme is not affected by the modulators 6-phosphogluconate and fructose 1,6-bisphosphate at low concentrations at which these agents stimulate the carboxylation rate. At higher concentrations these sugar phosphates protect the enzyme against pyridoxal 5'-phosphate inhibition in a similar fashion like the substrate ribulose 1,5-bisphosphate. Such protection experiments in combination with spectrophotometrical studies of pyridoxal 5'-phosphate binding demonstrate two binding states of ribulose 1,5-bisphosphate at the reaction centers of the enzyme with different requirements for Mg2+. 6-Phosphogluconate functions as protector only in the presence of Mg2+. Our results imply a competition between pyridoxal 5'-phosphate and substrate or effector sugar phosphates at the reaction centers of the spinach carboxylase. It is proposed that the pyridoxal 5'-phosphate inhibition of the stimulatory activity of these effectors originates from a modification of the regulatory sites of the enzyme caused by pyridoxal 5'-phosphate binding to the catalytical sites.

Binding Sites↗