Papers by Ivarne Tersariol
Studies on the heparin biosynthesis
Mo1794 Heparin Fragments Effects in Liver Injury Secondary to Liver Ischemia/Reperfusion (I/R)
Gastroenterology, 2014
Background: Sleep is a physiological event that directly influences health by affecting the immun... more Background: Sleep is a physiological event that directly influences health by affecting the immune system, in
which calcium (Ca2+) plays a critical signaling role. We performed live cell measurements of cytosolic Ca2+
mobilization to understand the changes in Ca2+ signaling that occur in splenic immune cells after various
periods of sleep deprivation (SD).
Methods: Adult male mice were subjected to sleep deprivation by platform technique for different periods
(from 12 to 72 h) and Ca2+ intracellular fluctuations were evaluated in splenocytes by confocal microscopy.
We also performed spleen cell evaluation by flow cytometry and analyzed intracellular Ca2+ mobilization in
endoplasmic reticulum and mitochondria. Additionally, Ca2+ channel gene expression was evaluated
Results: Splenocytes showed a progressive loss of intracellular Ca2+ maintenance from endoplasmic reticulum
(ER) stores. Transient Ca2+ buffering by the mitochondria was further compromised. These findings
were confirmed by changes in mitochondrial integrity and in the performance of the store operated calcium
entry (SOCE) and stromal interaction molecule 1 (STIM1) Ca2+ channels.
Conclusions and general significance: These novel data suggest that SD impairs Ca2+ signaling, most likely as a
result of ER stress, leading to an insufficient Ca2+ supply for signaling events. Our results support the previously
described immunosuppressive effects of sleep loss and provide additional information on the cellular
and molecular mechanisms involved in sleep function.
Development of an enzyme-linked immunosorbent assay for benalaxyl and its application to the analysis of water and wine
Analytica Chimica Acta, 1999
Structure of heparan sulfate: identification of variable and constant oligosaccharide domains in eight heparan sulfates of different origins
Cellular and molecular biology (Noisy-le-Grand, France), 1998
The use of specific enzymes (heparinase and heparitinases from Flavobacterium heparinum, endogluc... more The use of specific enzymes (heparinase and heparitinases from Flavobacterium heparinum, endoglucuronidase, alphaN-acetylglucosaminidase and beta-glucuronidase from the mollusc Anomalocardia brasiliana) and chemical methods (nitrous acid degradation, hydrazine N-deacetylation and borohydride reduction), led to the proposal of the total sequence of a heparan sulfate derived from bovine pancreas and partial sequences of heparan sulfates from different origins (bovine: lung, liver, brain; hog: liver, brain; rabbit liver; dog liver). It was shown that all the heparan sulfates contain common structural features such as: a N-acetylated and a N-sulfated domain made of glucuronic acid-containing disaccharides and a more sulfated region made of iduronic acid-containing disaccharides. Separating the two domains a peculiar tetrasaccharide made of GlcNAc-(alpha1-4)-IdoUA-(alpha1-4)-GlcNS-(alpha1-4)-IdoUA was identified in all the heparan sulfates analyzed. It was also shown that the non-reducin...
Maintainance of heparin through evolution: chemical, enzymatic and 1 H and 13 C NMR evidences
The reaction of cytochrome C and glycosaminoglycans. A kinetic and structural study
Cathepsins B and L as degrading enzymes in pancreatic endocrine function
Cathepsins β as degrading insulin in pancreatic endocrine function
Organic telluranes: a novel class of protease inhibitors
Spectroscopic and mathematical approaches for the detection and identification of heparin contaminants
Spectroscopy characterization of BSA-hemin copper substituted complex
Phytotherapy Research, 1997
The powdered bark obtained from Maquira sclerophylla Ducke is a snuff used by Amazonian natives. ... more The powdered bark obtained from Maquira sclerophylla Ducke is a snuff used by Amazonian natives. Pharmacological studies on rodents, guinea-pigs, rabbits and dogs revealed cardiovascular changes as the major effects produced by the polar phase of the bark ethanol extract. Oriented by this pharmacological activity a cardenolide fraction was chemically purified from the crude extract. Both crude extract and the purified fraction produced a positive inotropic effect in isolated heart preparations from guinea-pigs and rabbits, and inhibited the Na + , K + -ATPase activity of the enzyme isolated from bovine ventricles. The fraction yielded two major purified cardenolides identified as Maquiroside A (C 30 H 46 O 8 ) and Cymarin (C 30 H 44 O 9 ). Simultaneous intracellular recordings of the resting membrane potential (RMP) and miniature endplate potentials in rat diaphragm muscle fibres showed that the effect of the purified fraction predominated on the motor nerve terminals enhancing the spontaneous transmitter release, without major changes of RMP values. Comparatively, the effect of ouabain prevailed on the muscle fibre membrane. Considering that both effects depend on the Na + , K + -ATPase activity, the results indicated that the compounds derived from Maquira exert differential actions on this enzyme in the nerve and muscle membrane. These observations may explain the use of this toxic snuff in native festivities.
Journal of Enzyme Inhibition and Medicinal Chemistry, 2013
Cruzain is the major cysteine protease of Trypanosoma cruzi, the infectious agent responsible for... more Cruzain is the major cysteine protease of Trypanosoma cruzi, the infectious agent responsible for Chagas disease, and cruzain inhibitors display considerable antitrypanosomal activity. In the present work we elucidated crystallographic data of fukugetin, a biflavone isolated from Garcinia brasiliensis, and investigated the role of this molecule as cysteine protease inhibitor. The kinetic analyses demonstrated that fukugetin inhibited cruzain and papain by a slow reversible type inhibition with K I of 1.1 and 13.4 µM, respectively. However, cruzain inhibition was about 12 times faster than papain inhibition. Lineweaver-Burk plots demonstrated partial competitive inhibition for cruzain and hyperbolic mixed-type inhibition for papain. Furthermore, the docking results showed that the biflavone binds to ring C′ in the S2 pocket and to ring C in the S3 pocket through hydrophobic interactions and hydrogen bonds. Finally, fukugetin also presented inhibitory activity on proteases of the T. cruzi extract, with IC 50 of 7 µM.
Journal of Biological Chemistry, 2002
Trypanosoma cruzi activates the kinin pathway through the activity of its major cysteine proteina... more Trypanosoma cruzi activates the kinin pathway through the activity of its major cysteine proteinase, cruzipain. Because kininogen molecules may be displayed on cell surfaces by binding to glycosaminoglycans, we examined whether the ability of cruzipain to release kinins from high molecular weight kininogen (HK) is modulated by heparan sulfate (HS). Kinetic assays show that HS reduces the cysteine proteinase inhibitory activity (K i app ) of HK about 10-fold. Conversely, the catalytic efficiency of cruzipain on kinin-related synthetic fluorogenic substrates is enhanced up to 6-fold in the presence of HS. Analysis of the HK breakdown products generated by cruzipain indicated that HS changes the pattern of HK cleavage products. Direct measurements of bradykinin demonstrated an up to 35fold increase in cruzipain-mediated kinin liberation in the presence of HS. Similarly, kinin release by living trypomastigotes increased up to 10-fold in the presence of HS. These studies suggest that the efficiency of T. cruzi to initiate kinin release is potently enhanced by the mutual interactions between cruzipain, HK, and heparan sulfate proteoglycans.
Journal of Biological Chemistry, 1999
Papain is considered to be the archetype of cysteine proteinases. The interaction of heparin and ... more Papain is considered to be the archetype of cysteine proteinases. The interaction of heparin and other glycosaminoglycans with papain may be representative of many mammalian cysteine proteinase-glycosaminoglycan interactions that can regulate the function of this class of proteinases in vivo. The conformational changes in papain structure due to glycosaminoglycan interaction were studied by circular dichroism spectroscopy, and the changes in enzyme behavior were studied by kinetic analysis, monitored with fluorogenic substrate. The presence of heparin significantly increases the ␣-helix content of papain. Heparin binding to papain was demonstrated by affinity chromatography and shown to be mediated by electrostatic interactions. The incubation of papain with heparin promoted a powerful increase in the affinity of the enzyme for the substrate. In order to probe the glycosaminoglycan structure requirements for the papain interaction, the effects of two other glycosaminoglycans were tested. Like heparin, heparan sulfate, to a lesser degree, was able to decrease the papain substrate affinity, and it simultaneously induced ␣-helix structure in papain. On the other hand, dermatan sulfate was not able to decrease the substrate affinity and did not induce ␣-helix structure in papain. Heparin stabilizes the papain structure and thereby its activity at alkaline pH.
Journal of Biological Chemistry, 2001
Processamento Automático Para Quantificação de Marcadores e Classificação de Tumores em Imagens Imuno-histoquímicas
Estudo Do Efeito Antiarrítmico De Enoxaparina Em Arritmias Cardíacas Induzidas Por Fenotiazinas
Page 1. ESTUDO DO EFEITO ANTIARRÍTMICO DE ENOXAPARINA EM ARRITMIAS CARDÍACAS INDUZIDAS POR FENOTI... more Page 1. ESTUDO DO EFEITO ANTIARRÍTMICO DE ENOXAPARINA EM ARRITMIAS CARDÍACAS INDUZIDAS POR FENOTIAZINAS Marília Pissato Ferreira 1 ; Ivarne LS Tersariol 2 ; Tiago Rodrigues 3 ; Carlos Marcelo G. de Godoy 4 . ...
A Proposed Mechanism for Flavobacterium Heparinum Lyases: Heparitinase I and Heparinase
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Papers by Ivarne Tersariol
which calcium (Ca2+) plays a critical signaling role. We performed live cell measurements of cytosolic Ca2+
mobilization to understand the changes in Ca2+ signaling that occur in splenic immune cells after various
periods of sleep deprivation (SD).
Methods: Adult male mice were subjected to sleep deprivation by platform technique for different periods
(from 12 to 72 h) and Ca2+ intracellular fluctuations were evaluated in splenocytes by confocal microscopy.
We also performed spleen cell evaluation by flow cytometry and analyzed intracellular Ca2+ mobilization in
endoplasmic reticulum and mitochondria. Additionally, Ca2+ channel gene expression was evaluated
Results: Splenocytes showed a progressive loss of intracellular Ca2+ maintenance from endoplasmic reticulum
(ER) stores. Transient Ca2+ buffering by the mitochondria was further compromised. These findings
were confirmed by changes in mitochondrial integrity and in the performance of the store operated calcium
entry (SOCE) and stromal interaction molecule 1 (STIM1) Ca2+ channels.
Conclusions and general significance: These novel data suggest that SD impairs Ca2+ signaling, most likely as a
result of ER stress, leading to an insufficient Ca2+ supply for signaling events. Our results support the previously
described immunosuppressive effects of sleep loss and provide additional information on the cellular
and molecular mechanisms involved in sleep function.