Isolation, solubility and in vitro hydrolysis of chickpea vicilin-like protein

The chickpea vicilin-like globulin was isolated and chromatographed on Sepharose CL-6B and Sephacryl S-300. The native globulin with a molecular weight of 140 kDa was resolved in Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in seven polypeptide bands in the range of 12.4-67 kDa. The solubility profile of the protein in water and NaCl solutions was typical of a legume globulin. The purified vicilin-like globulin, native and heated, was hydrolyzed by pepsin, trypsin and chymotrypsin. The hydrolysis patterns indicated that the native vicilin-like protein was only partially degraded by the enzymes in comparison with casein. Heating increased its susceptibility to hydrolysis relative to the native form, for all the enzymes. However, the results obtained by the pH-drop method revealed that the in vitro digestibility of the vicilin-like protein was not altered by heating, while 11 S-like and total globulins suffered a small increase, indicating that the structural characteristics of storage globulins may be important factors limiting the protein digestion. (c) 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.

Enolase from Paracoccidioides brasiliensis: isolation and identification as a fibronectin-binding protein

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação do meio Agar Xilose Lisina Verde Brilhante no isolamento de Salmonella

Ao pesquisar-se a presença de Salmonella a partir de materiais diversos, foram empregados vários meios de cultura e entre eles o meio Agar Xilose Lisina Verde Brilhante, com a finalidade de avaliá-lo em relação a outros meios seletivo-indicadores mais comumente empregados no isolamento desses microrganismos. Os resultados mostraram que o meio Agar Xilose Lisina Verde Brilhante foi inferior aos Agar SS e Agar Verde Brilhante, ligeiramente superior ao Agar EMB e superior ao Agar Sulfito de Bismuto no isolamento de Salmonella. Grande vantagem adicional desse meio é que as colônias de Salmonella apresentam-se facilmente identificáveis.

Selective activity of butyrylcholinesterase in serum by a chemiluminescent assay

In a previous study, we showed that purified commercial esterase activity can be detected in a chemiluminescent assay based on the hydrolysis of 2-methyl-1-propenylbenzoate (MPB) to 2-methyl-1-propenol, which is subsequently oxidized by the horseradish peroxidase (HRP)-H2O2 system. The purpose of this study was to verify the applicability of this assay to human serum. The existence of an esterase activity capable of hydrolysing MPB is indicated by the fact that the MPB-scruin-HRP-H2O2 System consumes oxygen and emits light. Both signals were abolished by prior serum heat inactivation and were preserved when serum was stored at less than or equal to4 degreesC. Addition of aliesterase inhibitors, such as fluoride ion and trichlorfon or the cholinesterase inhibitor eserine, totally prevents light emission. The butyrylcholinesterase-specific substrate benzoylcholine causes a delay in both O-2 uptake and light emission, while the specific acetylcholinesterase substrate, acetyl-beta -methylcholine, had practically no effect. Purified butyrylcholinesterase, but not acetylcholinesterase, triggered light emission. The finding that butyryleholinesterase is responsible for the hydrolysis of MPB in serum should serve as the basis for the development of a specific chemiluminescent assay for this enzyme. Copyright (C) 2001 John Wiley & Sons, Ltd.

Isolation and partial characterization of a 30 kDa adhesin from Paracoccidioides brasiliensis

The virulence of Paracoccidioides brasiliensis can be attenuated or lost after long periods of repeated subculturing and reestablished after animal inoculation. Only one adhesin (gp43) has been described until now, among the various identified components of P. brasiliensis, and gp43 shows adhesion to laminin. Thus, the present study was designed to isolate and characterize factors putatively related to the capacity of this fungus to adhere to the host by comparing P brasiliensis samples, taken before and after animal inoculation. The two samples differed in their pattern of adhesion and invasion. The sample recently isolated from animals (Pb18b) demonstrated a greater capacity to adhere and to invade the Vero cells than the one subcultured in vitro (Pb18a). Extract from Ph18b also showed higher levels of protein expression than that from Pb18a, when two-dimensional electrophoresis gels were compared. A protein species of 30 kDa, pI 4.9, was more evident in the Pb18b extract and had properties of adhesin. Laminin, but none of the other extracellular matrix (ECM) components, such as fibronectin, collagen I and IV, bound specifically to the P. brasiliensis 30 kDa protein. The roles of 30 kDa and gp43 in cellular interactions were investigated and the adhesion of P. brasiliensis yeast cells was intensively inhibited by pre-treatment of epithelial cells with 30 kDa protein and gp43. Thus, this study presents evidence that adhesion capacity could be related to virulence, and that a 30 kDa adhesin accumulated differentially in samples with different levels of pathogenicity. This protein and its adhesion characteristics are being published for the first time and may be related to the virulence of P brasiliensis. (c) 2005 Elsevier SAS. All rights reserved.

Rapid and Selective UV Spectrophotometric Method for the Analysis of Ceftazidime

A new UV spectrophotometric method was developed for quantitative evaluation of ceftazidime preparations. The UV detector was set at 255 nm. Beer's law is obeyed in the concentration range of 7.0-14.0 mu g/mL. The method was found to be selective, linear, accurate, and precise in the specified ranges. Intra- and interday variability for the method were <2% relative standard deviation. Common excipients used as additives in pharmaceutical preparations do not interfere with the proposed method. This method was successfully used for quantification of ceftazidime in pure form and in pharmaceutical preparations.

Rhodococcus equi isolation from sputum of patients with suspected tuberculosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Isolation and isoenzyme characterization of Leishmania (Viannia) braziliensis from a case of human cutaneous leishmaniasis in northeast centre of the state of São Paulo

The diagnosis of human cutaneous leishmaniasis in small towns is sometimes made without the species identification of the Leishmania, even in areas without previous epidemiological surveys. Here we report the isolation of a Leishmania strain from a patient of Rincão, state of São Paulo, that was identified by isoenzyme characterization as L. (Viannia) braziliensis. Sand fly collections were made in the area where the patient live in order to investigate the likely vector species.

An experimental switchable stiffness device for shock isolation

The development of an experimental switching stiffness device fcr shock isolation is presented. The system uses magnetic forces to exert a restoring force, which results in an effective stiffness that is used to isolate a payload. When the magnetic force is turned on and off, a switchable stiffness is obtained. Characterization of the physical properties of the device is presented. They are estimated in terms of the percentage stiffness change and effective damping ratio when switched between two constant stiffness states. Additionally, the setup is used to implement a control strategy to reduce the shock response and minimize residual vibration. The system was found to be very effective for shock isolation. The response is reduced by around 50 percent compared with passive isolation showing good correlation with theoretical predictions, and the effective damping ratio in the system following the shock was increased from about 4.5 percent to 13 percent. (c) 2012 Elsevier Ltd. All rights reserved.