Publications by authors named "Sara Lucena"

Crotamine and crotamine-like peptides are non-enzymatic polypeptides, belonging to the family of myotoxins, which are found in high concentration in the venom of the Crotalus genus. Helleramine was isolated and purified from the venom of the Southern Pacific rattlesnake, Crotalus oreganus helleri. This peptide had a similar, but unique, identity to crotamine and crotamine-like proteins isolated from other rattlesnakes species.

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Crotamine is a cationic, non-enzymatic, protein integrating a minor family of myotoxins, composed of 42 amino acid residues, described in Viperidae and Crotalidae snake's families that has been used in neuroscience research, drug progressing and molecular diversity reports. Crotamine-like protein (CLP) from C.o.

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Disintegrins represent a family of effective cell-cell and cell-matrix inhibitors by binding to integrin receptors. Integrins are heterodimeric, transmembrane receptors that are the bridges for these cell interactions. Disintegrins have been shown to have many therapeutic implications for the treatment of strokes, heart attacks, and cancer.

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Snake venoms are known to have different venom compositions and toxicity, but differences can also be found within populations of the same species contributing to the complexity of treatment of envenomated victims. One of the first well-documented intraspecies venom variations comes from the Mohave rattlesnake (Crotalus scutulatus scutulatus). Initially, three types of venoms were described; type A venom is the most toxic as a result of ~45% Mojave toxin in the venom composition, type B lacks the Mojave toxin but contains over 50% of snake venom metalloproteases (SVMPs).

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We have demonstrated in previous studies that a single amino acid change can alter the activity of the recombinant disintegrin r-Moj. In this study, four r-Moj recombinants containing single mutations (r-Moj-WL, r-Moj-WM, r-Moj-WP, r-Moj-MN) and two containing double mutations (r-Moj-MP and r-Moj-NM) at the binding loop were produced, purified, and tested. All r-Moj-W_, r-Moj-M_, and r-Moj-NM mutant peptides inhibited platelet aggregation at higher potency than r-Moj-D_ mutants.

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Crotalid venoms are rich sources of components that affect the hemostatic system. Snake venom metalloproteinases are zinc-dependent enzymes responsible for hemorrhage that also interfere with hemostasis. The disintegrin domain is a part of snake venom metalloproteinases, which involves the binding of integrin receptors.

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Phenotypes frequently vary across and within species. The connection between specific phenotypic effects and function, however, is less understood despite being essential to our understanding of the adaptive process. Snake venoms are ideal for identifying functionally important phenotypic variation because venom variation is common, and venoms can be functionally characterized through simple assays and toxicity measurements.

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Disintegrins are small peptides produced in viper venom that act as integrin antagonists. When bound to integrins, disintegrins induce altered cellular behaviors, such as apoptotic induction. Disintegrins with RGDDL or RGDDM motifs induce apoptosis of normal and cancer cells.

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The vast amounts of toxins within the venom of snakes, while known to cause medical emergencies, display various biological functions. Trans-pecos copperhead (Agkistrodon contortrix pictigaster) crude venom separated by cation-exchange chromatography showed several fractions with fibrinolytic, hemorrhagic, gelatinase and platelet activities. Venom fractions 1, 2, 4, 5, and 12-17 contained fibrinolytic activity.

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Background: Bothrops colombiensis is a highly dangerous pit viper and responsible for over 70% of snakebites in Venezuela. Although the composition in B. colombiensis venom has been identified using a proteome analysis, the venom gland transcriptome is currently lacking.

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The Tamaulipan rock rattlesnake () is a montane snake that occurs in the humid pine-oak forest and the upper cloud forest of the Sierra Madre Oriental in southwestern Tamaulipas, central Nuevo Leon, and southeastern Coahuila in Mexico. Venom from this rattlesnake was fractionated by High-Performance Liquid Chromatography for the purpose of discovering disintegrin molecules. Disintegrins are non-enzymatic, small molecular weight peptides that interfere with cell-cell and cell-matrix interactions by binding to various cell receptors.

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Intimate partner violence is an important cause of morbidity and mortality among women. Although there are no official statistics, data reveal a high prevalence worldwide. This study aimed to estimate the prevalence and factors associated with intimate partner violence among women in a community in Recife, Pernambuco.

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Pancreatic cancer is a malignant cancer common worldwide having poor prognosis, even when diagnosed at its early stage. Cell adhesion plays a critical role in cancer invasion and metastasis. Integrins are major mediators of cell adhesion and play an important role in invasion and metastatic growth of human pancreatic cancer cells.

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Pancreatic cancer often has a poor prognosis, even when diagnosed early. Pancreatic cancer typically spreads rapidly and is rarely detected in its early stages, which is a major reason it is a leading cause of cancer death. Signs and symptoms may not appear until pancreatic cancer is quite advanced, and complete surgical removal is not possible.

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Angiogenesis plays a crucial role in the growth and spread of cancer. New vascularization nourishes cancer cells with oxygen and nutrients, allowing these cells to grow, invade nearby tissue, spread to other parts of the body, and form new colonies of cancer cells. Tumor angiogenesis consists of endothelial cell proliferation, migration, and tube formation into the tumor mass.

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A 5' truncated snake venom metalloproteinase was identified from a cDNA library constructed from venom glands of an eastern diamondback rattlesnake (Crotalus adamanteus). The 5'-rapid amplification of cDNA ends (RACE) was used to obtain the 1865 bp full-length cDNA sequence of a snake venom metalloproteinase (CamVMPII). CamVMPII encodes an open reading frame of 488 amino acids, which includes a signal peptide, a pro-domain, a metalloproteinase domain, a spacer, and an RGD-disintegrin domain.

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Snake venom disintegrins inhibit platelet aggregation and have anti-cancer activities. In this study, we report the cloning, expression, and functional activities of a recombinant disintegrin, r-viridistatin 2 (GenBank ID: JQ071899), from the Prairie rattlesnake. r-Viridistatin 2 was tested for anti-invasive and anti-adhesive activities against six different cancer cell lines (human urinary bladder carcinoma (T24), human fibrosarcoma (HT-1080), human skin melanoma (SK-Mel-28), human colorectal adenocarcinoma (CaCo-2), human breast adenocarcinoma (MDA-MB-231) and murine skin melanoma (B16F10)).

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Disintegrins are low molecular weight peptides isolated from viper venom. These peptides bind to integrin receptors using a conserved binding motif sequence containing an RGD or similar motif. As a consequence, disintegrins can inhibit platelet aggregation and inhibit cell migration, proliferation, and initiate apoptosis in cancer cell lines.

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Venom phospholipases A2 (PLA(2)) are associated with neurotoxic, myotoxic, cardiotoxic, platelet aggregation, and edema activities. A PLA(2) (Drs-PLA(2)) was purified from Daboia russelii siamensis venom by a two-step purification procedure consisting of size-exclusion, followed by anion exchange high performance liquid chromatography (HPLC). The molecular weight of the Drs-PLA(2) was 13,679Da, which was determined by MALDI-TOF mass spectrometry.

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Platelets play a central role in hemostasis during vascular injury. Patients affected with the hemorrhagic syndrome caused by contact with Lonomia achelous caterpillars (Lac) Lepidoptera distributed in various South American countries, show digestive, pulmonary and intraperitoneal bleeding in combination with hematomas and echymosis. In the present study, we have evaluated the effects of Lonomin V (serine protease isolated from Lac hemolymph) on some functional properties of platelets, evaluating its importance in primary hemostasis.

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Cancer is the uncontrollable growth of cell, which may spread to other parts of the body. The interaction of cancer cells with extracellular matrix (ECM) is essential for metastasis, which is the principal cause of death in cancer patients. Disintegrins are naturally occurring low molecular weight peptides found in the venoms of many snakes.

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Disintegrins and disintegrin-like peptides interact with integrins and interfere with cell-cell and cell-matrix interactions. A disintegrin-like snake venom gene, Acocostatin was cloned from the venom gland mRNA of Agkistrodon contortrix contortrix. Acocostatin belongs to the PIII-SVMP subfamily of disintegrin-like peptides.

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Interactions with exposed subendothelial extracellular proteins and cellular integrins (endothelial cells, platelets and lymphocytes) can cause alterations in the hemostatic system associated with atherothrombotic processes. Many molecules found in snake venoms induce pathophysiological changes in humans, cause edema, hemorrhage, and necrosis. Disintegrins are low molecular weight, non-enzymatic proteins found in snake venom that mediate changes by binding to integrins of platelets or other cells and prevent binding of the natural ligands such as fibrinogen, fibronectin or vitronectin.

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In this study, three recombinant mojastin peptides (Moj-WN, Moj-NN, and Moj-DM) were produced and compared functionally. Recombinant Moj peptides were purified as GST-fusions. GST-Moj-WN and GST-Moj-NN inhibited ADP-induced platelet aggregation in platelet rich plasma.

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