Novi lizozim s antifungalnim svojstvima, izoliran iz sjemenki biljke Pithecellobium dulce

A protein of an apparent molecular mass of 14.4 kDa with antifungal activity was isolated from the seeds of Pithecellobium dulce using extraction with 100 mM Tris-HCl buffer (pH=8.0), precipitation with 80 % ammonium sulfate, and bioassay purification via Resource Q anion exchange chromatography and Superdex 200 gel filtration chromatography. The purified protein was putatively identified by tandem mass spectrometry with Mascot database searching, with the partial amino acid sequences showing a high degree of similarity to chicken egg white lysozyme. This putative plant lysozyme expressed antifungal activity with a rather high thermal stability of up to 80 °C for 15 min (at pH=8.0). It exerted an antifungal action towards Macrophomina phaseolina but displayed no antifungal activity against two other isolates, Phymatotrichopsis omnivora and Fusarium avenaceum.Iz sjemenki biljke Pithecellobium dulce ekstrakcijom sa 100 mM Tris puferom (pH=8), zatim taloženjem pomoću 80 %-tnog amonijeva sulfata i pročišćavanjem anionsko-izmjenjivačkom Resource Q i gel-filtracijskom Superdex 200 kromatografijom izoliran je protein relativne molekularne mase od 14,4 kDa, koji ima antifungalna svojstva. Pročišćeni je protein identificiran pomoću tandemske spektrometrije masa, pri čemu je upotrijebljena baza podataka Mascot. Utvrđeno je da djelomična sekvencija aminokiselina ispitivanoga proteina izrazito nalikuje sekvenciji lizozima bjelanjka kokošjeg jajeta. Lizozim iz biljke imao je antifungalna svojstva i bio je stabilan pri pH=8 tijekom 15 minuta na temperaturama čak do 80 °C. Spriječio je rast plijesni Macrophomina phaseolina, ali ne i vrsta Phymtotrichopsis omnivora i Fusarium avenaceum

Discovery, isolation and structural characterization of cyclotides from Viola sumatrana miq

Cyclotides are cyclic peptides from plants in the Violaceae, Rubiaceae, Fabaceae, Cucurbitaceae, and Solanaceae families. They are sparsely distributed in most of these families, but appear to be ubiquitous in the Violaceae, having been found in every plant so far screened from this family. However, not all geographic regions have been examined and here we report the discovery of cyclotides from a Viola species from South-East Asia. Two novel cyclotides (Visu 1 and Visu 2) and two known cyclotides (kalata S and kalata B1) were identified in V. sumatrana. NMR studies revealed that kalata S and kalata B1 had similar secondary structures. Their biological activities were determined in cytotoxicity assays; both had similar cytotoxic activity and were more toxic to U87 cells compared with other cell lines. Overall, the study strongly supports the ubiquity of cyclotides in the Violaceae and adds to our understanding of their distribution and cytotoxic activity

A Lysozyme with Antifungal Activity from Pithecellobium dulce Seeds

A protein of an apparent molecular mass of 14.4 kDa with antifungal activity was isolated from the seeds of Pithecellobium dulce using extraction with 100 mM Tris-HCl buffer (pH=8.0), precipitation with 80 % ammonium sulfate, and bioassay purification via Resource Q anion exchange chromatography and Superdex 200 gel filtration chromatography. The purified protein was putatively identified by tandem mass spectrometry with Mascot database searching, with the partial amino acid sequences showing a high degree of similarity to chicken egg white lysozyme. This putative plant lysozyme expressed antifungal activity with a rather high thermal stability of up to 80 °C for 15 min (at pH=8.0). It exerted an antifungal action towards Macrophomina phaseolina but displayed no antifungal activity against two other isolates, Phymatotrichopsis omnivora and Fusarium avenaceum

Discovery and characterization of cyclotides from Rinorea species

Cyclotides are macrocyclic cystine-knotted peptides most commonly found in the Violaceae plant family. Although Rinorea is the second-largest genera within the Violaceae family, few studies have examined whether or not they contain cyclotides. To further our understanding of cyclotide diversity and evolution, we examined the cyclotide content of two Rinorea species found in Southeast Asia: R. virgata and R. bengalensis. Seven cyclotides were isolated from R. virgata (named Rivi1-7), and a known cyclotide (cT10) was found in R. bengalensis. Loops 2, 5, and 6 of Rivi1-4 contained sequences not previously seen in corresponding loops of known cyclotides, thereby expanding our understanding of the diversity of cyclotides. In addition, the sequence of loop 2 of Rivi3 and Rivi4 were identical to some related noncyclic "acyclotides" from the Poaceae plant family. As only acyclotides, but not cyclotides, have been reported in monocotyledons thus far, our findings support an evolutionary link between monocotyledon-derived ancestral cyclotide precursors and dicotyledon-derived cyclotides. Furthermore, Rivi2 and Rivi3 had comparable cytotoxic activities to the most cytotoxic cyclotide known to date: cycloviolacin O2 from Viola odorata; yet, unlike cycloviolacin O2, they did not show hemolytic activity. Therefore, these cyclotides represent novel scaffolds for use in future anticancer drug design