Gabriel Padilla

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Surprisingly little is known of the toxic arsenal of cnidarian nematocysts compared to other venomous animals. Here we investigate the toxins of nematocysts isolated from the jellyfish Olindias sambaquiensis. A total of 29 unique ms/ms events were annotated as potential toxins homologous to the toxic proteins from diverse animal phyla, including(More)
Certain bacteria present on frog skin can prevent infection by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), conferring disease resistance. Previous studies have used agar-based in vitro challenge assays to screen bacteria for Bd-inhibitory activity and to identify candidates for bacterial supplementation trials. However, agar-based assays can(More)
The effects of u.v. light and of several chemical agents on spores of the tetracycline producer Streptomyces aureofaciens MT1 were studied using survival curves and induction of histidine prototrophic revertants (his (+)). Spores were highly resistant to u.v.; NTG induced most his (+) revertants. 4-Nitroquinoline-1-oxide and methyl methanesulphonate also(More)
Oligopeptide-binding protein (OppA) is the periplasmic component of the major oligopeptide transport system of enteric bacteria. Genetic and biochemical evidence suggests that OppA plays a role in the uptake of aminoglycoside antibiotics in Escherichia coli K-12. Forty-six (82%) of 56 aminoglycoside-resistant mutants of E. coli K-12 selected in vitro had(More)
For any smooth free action of the unit circle S in a manifold M ; the Gysin sequence of M is a long exact sequence relating the DeRham cohomologies of M and its orbit space M/S. If the action is not free then M/S is not a manifold but a stratified pseudomanifold and there is a Gysin sequence relating the DeRham cohomology of M with the intersection(More)
Cosmomycin D (CosD) is the major constituent fraction isolated from a culture of Streptomyces olindensis ICB20. The ability of this compound to intercalate with double-stranded DNA was studied by gel mobility shift assays and electrospray ionization mass spectrometry (ESI-MS). ESI-MS experiments showed that the complex of CosD with 16-mer double-stranded(More)
An improved, rapid and inexpensive gel mobility shift assay was developed for the screening of anthracycline antibiotics. The assay based on the intercalation activity of these molecules into dsDNA was used to assess the activity of partially purified antibiotics. Detection limits were of 0.1 ng ml−1 with an average run time of 2 h. The assay is potentially(More)
Glycosylation pattern in cosmomycins is a distinctive feature among anthracyclines. These antitumor compounds possess two trisaccharide chains attached at C-7 and C-10, each of them with structural variability, mainly at the distal deoxysugar moieties. We have characterized a 14-kb chromosomal region from Streptomyces olindensis containing 13 genes involved(More)
Cultures of cosmomycin D-producing Streptomyces olindensis ICB20 that were propagated for many generations underwent mutations that resulted in production of a range of related anthracyclines by the bacteria. The anthracyclines that retained the two trisaccharide chains of the parent compound were separated by HPLC. Exact mass determination of these(More)
The chemical ecology and biotechnological potential of metabolites from endophytic and rhizosphere fungi are receiving much attention. A collection of 17 sugarcane-derived fungi were identified and assessed by PCR for the presence of polyketide synthase (PKS) genes. The fungi were all various genera of ascomycetes, the genomes of which encoded 36 putative(More)