Molecular Architecture of the Antiophidic Protein DM64 and its Binding Specificity to Myotoxin II From Venom.

DM64 is a toxin-neutralizing serum glycoprotein isolated from , an ophiophagous marsupial naturally resistant to snake envenomation. This 64 kDa antitoxin targets myotoxic phospholipases A, which account for most local tissue damage of viperid snakebites. We investigated the noncovalent complex formed between native DM64 and myotoxin II, a myotoxic phospholipase-like protein from venom.

ASP-Enzymosomes with Asparaginase II Expressed in : Formulation Design and In Vitro Studies of a Potential Antileukemic Drug.

The bacterial enzyme asparaginase is the main treatment option for acute lymphoblastic leukemia. However, it causes side effects, such as immunological reactions, and presents undesirable glutaminase activity. As an alternative, we have been studying asparaginase II from , coded by gene, which was cloned and expressed in The recombinant asparaginase (ASP) presented antileukemic activity and a glutaminase activity 100 times lower in comparison to its asparaginase activity.

The interaction between the natural metalloendopeptidase inhibitor BJ46a and its target toxin jararhagin analyzed by structural mass spectrometry and molecular modeling.

Snakebite envenoming affects millions of people worldwide, being officially considered a neglected tropical disease by the World Health Organization. The antivenom is effective in neutralizing the systemic effects of envenomation, but local effects are poorly neutralized, often leading to permanent disability. The natural resistance of the South American pit viper Bothrops jararaca to its venom is partly attributed to BJ46a, a natural snake venom metalloendopeptidase inhibitor.

Ferritin from the haemolymph of adult ants: an extraction method for characterization and a ferromagnetic study.

Ferritin has been studied in many animals, plants and bacteria. The main functions of ferritin in mammals are iron concentration and stabilization, protection against oxidants and iron storage for later developmental or iron-dependent activities. Although insect ferritin plays a key role in iron transport, only a few studies to date have examined its properties and function.

Heterologous expression of the antimyotoxic protein DM64 in Pichia pastoris.

Snakebite envenomation is a neglected condition that constitutes a public health problem in tropical and subtropical countries, including Brazil. Interestingly, some animals are resistant to snake envenomation due to the presence of inhibitory glycoproteins in their serum that target toxic venom components. DM64 is an acidic glycoprotein isolated from Didelphis aurita (opossum) serum that has been characterized as an inhibitor of the myotoxicity induced by bothropic toxins bearing phospholipase A2 (PLA2) structures.

Screening for target toxins of the antiophidic protein DM64 through a gel-based interactomics approach.

Unlabelled: DM64 is a glycosylated protein with antivenom activity isolated from the serum of the opossum Didelphis aurita. It binds non-covalently to myotoxins I (Asp49) and II (Lys49) from Bothrops asper venom and inhibits their myotoxic effect. In this study, an affinity column with immobilized DM64 as bait was used to fish potential target toxins.

Rhamnolipid production: effect of oxidative stress on virulence factors and proteome of Pseudomonas aeruginosa PA1.

Under specific environmental conditions, Pseudomonas aeruginosa produces a biodegradable surfactant rhamnolipid. Evidences suggest that this biosurfactant is involved in protecting cells against oxidative stress; however, the effects of oxidative stress on its production and other virulence factors are still unclear. Here we show that rhamnolipid production is dependent on the aeration surface when P.

Using mass spectrometry to explore the neglected glycan moieties of the antiophidic proteins DM43 and DM64.

The resistance of the opossum Didelphis aurita to Bothrops snake venoms is attributed to the opossum's antihemorrhagic (DM43) and antimyotoxic (DM64) acidic serum glycoproteins. The aim of this study was to characterize the N-glycosylation sites of these antiophidic proteins and to determine whether their glycans influence the biological activity measured by in vitro assays. Our experimental pipeline included the sequential enzymatic digestion of the inhibitors with two different proteinases (trypsin and endoproteinase Asp-N) and eventually with trypsin, peptide-N-glycosidase F (PNGase F) and endoproteinase Asp-N, used in that order.

Venomics profiling of Thamnodynastes strigatus unveils matrix metalloproteinases and other novel proteins recruited to the toxin arsenal of rear-fanged snakes.

Rear-fanged and aglyphous snakes are usually considered not dangerous to humans because of their limited capacity of injecting venom. Therefore, only a few studies have been dedicated to characterizing the venom of the largest parcel of snake fauna. Here, we investigated the venom proteome of the rear-fanged snake Thamnodynastes strigatus , in combination with a transcriptomic evaluation of the venom gland.

Antibodies against the Plasmodium falciparum glutamate-rich protein from naturally exposed individuals living in a Brazilian malaria-endemic area can inhibit in vitro parasite growth.

The glutamate-rich protein (GLURP) is an exoantigen expressed in all stages of the Plasmodium falciparum life cycle in humans. Anti-GLURP antibodies can inhibit parasite growth in the presence of monocytes via antibody-dependent cellular inhibition (ADCI), and a major parasite-inhibitory region has been found in the N-terminal R0 region of the protein. Herein, we describe the antiplasmodial activity of anti-GLURP antibodies present in the sera from individuals naturally exposed to malaria in a Brazilian malaria-endemic area.

Conformational plasticity of DM43, a metalloproteinase inhibitor from Didelphis marsupialis: chemical and pressure-induced equilibrium (un)folding studies.

We have investigated the folding of DM43, a homodimeric metalloproteinase inhibitor isolated from the serum of the South American opossum Didelphis marsupialis. Denaturation of the protein induced by GdnHCl (guanidine hydrochloride) was monitored by extrinsic and intrinsic fluorescence spectroscopy. While the equilibrium (un)folding of DM43 followed by tryptophan fluorescence was well described by a cooperative two-state transition, bis-ANS (4,4'-dianilino-1,1'-binaphthyl-5,5'-disulfonic acid) fluorescence measurements revealed an intensity maximum at the midpoint of the unfolding transition (2 M GdnHCl), indicating a partially folded intermediate state.

Crotalid snake venom subproteomes unraveled by the antiophidic protein DM43.

Snake venoms are mixtures of proteins and peptides with different biological activities, many of which are very toxic. Several animals, including the opossum Didelphis aurita, are resistant to snake venoms due to the presence of neutralizing factors in their blood. An antihemorrhagic protein named DM43 was isolated from opossum serum.

Bothrops insularis venomics: a proteomic analysis supported by transcriptomic-generated sequence data.

A joint transcriptomic and proteomic approach employing two-dimensional electrophoresis, liquid chromatography and mass spectrometry was carried out to identify peptides and proteins expressed by the venom gland of the snake Bothrops insularis, an endemic species of Queimada Grande Island, Brazil. Four protein families were mainly represented in processed spots, namely metalloproteinase, serine proteinase, phospholipase A(2) and lectin. Other represented families were growth factors, the developmental protein G10, a disintegrin and putative novel bradykinin-potentiating peptides.

Protein expression profile of Gluconacetobacter diazotrophicus PAL5, a sugarcane endophytic plant growth-promoting bacterium.

This is the first broad proteomic description of Gluconacetobacter diazotrophicus, an endophytic bacterium, responsible for the major fraction of the atmospheric nitrogen fixed in sugarcane in tropical regions. Proteomic coverage of G. diazotrophicus PAL5 was obtained by two independent approaches: 2-DE followed by MALDI-TOF or TOF-TOF MS and 1-DE followed by chromatography in a C18 column online coupled to an ESI-Q-TOF or ESI-IT mass spectrometer.

Functional analysis of DM64, an antimyotoxic protein with immunoglobulin-like structure from Didelphis marsupialis serum.

Bothrops snake venoms are known to induce local tissue damage such as hemorrhage and myonecrosis. The opossum Didelphis marsupialis is resistant to these snake venoms and has natural venom inhibitors in its plasma. The aim of this work was to clone and study the chemical, physicochemical and biological properties of DM64, an antimyotoxic protein from opossum serum.