排序方式: 共有6条查询结果,搜索用时 156 毫秒
1
1.
Thiago Henrique Napoleão Teodomiro Gomes dos Santos-Filho Emmanuel Viana Pontual Rodrigo da Silva Ferreira Luana Cassandra Breitenbach Barroso Coelho Patrícia Maria Guedes Paiva 《Applied biochemistry and biotechnology》2013,171(3):744-755
This work reports the use of matrices containing Cratylia mollis lectins (Cramoll 1,2,3-Sepharose and Cramoll 3-Sepharose) for isolation of glycoproteins from fetal bovine serum, human colostrum, hen egg white, and human blood plasma. Cramoll 1,2,3-Sepharose was able to bind a glycoprotein from fetal bovine serum which showed the same fetuin electrophoretic profile. The data indicate that this protein adsorbed to the matrix by interaction with Cramoll 3. Cramoll 1,2,3-Sepharose was not efficient to retain glycoproteins from human colostrum or commercial ovalbumin. Cramoll 3-Sepharose bound ovalbumin, and the support retained protein from hen egg white. Protein peaks eluted from the column with 1.0 M NaCl or 0.3 M galactose showed apparent molecular mass of ovalbumin. Two main proteins from blood plasma with apparent molecular mass 67 (similar to albumin) and 50 kDa (similar to fetuin) adsorbed on Cramoll 3-Sepharose and were eluted with 1.0 M NaCl as a single peak. Elution of adsorbed plasma proteins with 0.3 M galactose was less selective than with 1.0 M NaCl as revealed by SDS-PAGE. In conclusion, the Cramoll 1,2,3-Sepharose and Cramoll 3-Sepharose matrices were useful to separate glycoproteins from complex protein mixtures, and the adsorption phenomena was a carbohydrate-dependent event. 相似文献
2.
Lívia Barros Salum Napoleão Fonseca Valadares 《Journal of computer-aided molecular design》2010,24(10):803-817
Alzheimer’s disease is an ultimately fatal neurodegenerative disease, and BACE-1 has become an attractive validated target
for its therapy, with more than a hundred crystal structures deposited in the PDB. In the present study, we present a new
methodology that integrates ligand-based methods with structural information derived from the receptor. 128 BACE-1 inhibitors
recently disclosed by GlaxoSmithKline R&D were selected specifically because the crystal structures of 9 of these compounds
complexed to BACE-1, as well as five closely related analogs, have been made available. A new fragment-guided approach was
designed to incorporate this wealth of structural information into a CoMFA study, and the methodology was systematically compared
to other popular approaches, such as docking, for generating a molecular alignment. The influence of the partial charges calculation
method was also analyzed. Several consistent and predictive models are reported, including one with r
2 = 0.88, q
2 = 0.69 and r
pred2 = 0.72. The models obtained with the new methodology performed consistently better than those obtained by other methodologies,
particularly in terms of external predictive power. The visual analyses of the contour maps in the context of the enzyme drew
attention to a number of possible opportunities for the development of analogs with improved potency. These results suggest
that 3D-QSAR studies may benefit from the additional structural information added by the presented methodology. 相似文献
3.
Kézia Santana de Moura Hugo Rafael Chaves da Silva Leonardo Prezzi Dornelles Luana Cassandra Breitenbach Barroso Coelho Thiago Henrique Napoleão Maria Danielly Lima de Oliveira Patrícia Maria Guedes Paiva 《Applied biochemistry and biotechnology》2016,180(7):1361-1371
Moringa oleifera seeds contain a water-soluble lectin [water-soluble M. oleifera lectin (WSMoL)] that has shown coagulant activity. Magnesium ions are able to interfere with the ability of this lectin to bind carbohydrates. In this study, we performed structural characterization of WSMoL and analyzed its effect on the electrical resistance of a kaolin clay suspension in both presence and absence of monosaccharides (N-acetylglucosamine, glucose, or fructose) and magnesium ions. The coagulant activity of WSMoL was monitored by measuring optical density and electrical resistance over a period of 60 min. Native WSMoL had a molecular mass of 60 kDa and exhibited anionic nature (pI 5.5). In sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), it appeared as three polypeptide bands of 30, 20, and 10 kDa. WSMoL reduced the optical density and electrical resistance of the kaolin suspension, which suggests that suspended particles are destabilized and that this is followed by formation of complexes. The coagulant activity of lectin decreased in the presence of Mg2+ ions and carbohydrates at concentrations that also inhibited hemagglutinating activity. This was most likely due to conformational changes in lectin structure. Our findings suggest that the coagulant activity of WSMoL is enhanced by lowering of electrical resistance of the medium and is impaired by lectin–carbohydrate and lectin–Mg2+ interactions. 相似文献
4.
Maria Inês Sucupira Maciel Maria do Socorro de Mendon?a Cavalcanti Thiago Henrique Napole?o Patrícia Maria Guedes Paiva Maria Teresa Jansem de Almeida Catanho Luana Cassandra Breitenbach Barroso Coelho 《Applied biochemistry and biotechnology》2012,168(3):580-591
Lectins, proteins that recognize carbohydrates, have been immobilized on inert supports and used in the screening or purification of glycoproteins. Anacardium occidentale bark infusion has been used as a hypoglycemic agent in Brazil. The toxicity of natural products may be evaluated determining their capability to alter the biodistribution of technetium-99M (99mTc). This work reports the isolation and characterization of a lectin from A. occidentale bark (AnocBL), its evaluation as an affinity support for glycoprotein isolation and lectin effect on the uptake of 99mTc by rat adipocytes. AnocBL was isolated from 80?% ammonium sulphate supernatant by affinity chromatography on fetuin?Cagarose. SDS?CPAGE showed a single protein band of 47?kDa. The monossacharide l-arabinose and the glycoproteins fetuin, asialofetuin, ovomucoid, casein, thyroglobulin, peroxidase, fetal bovine serum and IgG inhibited the activity. The lectin activity was stable until 70?°C and at a pH range of 3.0?C7.5. AnocBL?CSepharose column bound fetuin indicating that the lectin matrix may be used to obtain glycoconjugates of biotechnological interest. In vitro assay revealed that glucose and insulin increase 99mTc uptake by rat adipocytes. AnocBL decreases 99mTc uptake, and this effect was not detected in the presence of glucose. Fetuin inhibited AnocBL effect in all insulin concentrations. 相似文献
5.
Lidiane Pereira de Albuquerque Giselly Maria de Sá Santana Thiago Henrique Napoleão Luana Cassandra Breitenbach Barroso Coelho Márcia Vanusa da Silva Patrícia Maria Guedes Paiva 《Applied biochemistry and biotechnology》2014,172(2):1098-1105
Fusarium oxysporum f. sp. lycopersici races 1, 2, and 3 deteriorate tomato crops since they cause a vascular wilt. Lectins are carbohydrate-binding proteins with hemagglutinating and antifungal activities. This work reports that Microgramma vacciniifolia rhizome lectin (MvRL) inhibits F. oxysporum f. sp. lycopersici race 3 growth (61 %) more intensely than of races 1 (55 %) and 2 (45 %). The hemagglutinating activity of MvRL was inhibited by glycoprotein preparations from mycelia of races 1, 2, and 3, and these data indicate that lectin carbohydrate-binding sites recognized glycosylated molecules from races. Inter-simple sequence repeat (ISSR) marker system showed that race 3 is genetically distinct from races 1 and 2, and thus the highest sensitiveness of F. oxysporum f. sp. lycopersici race 3 to MvRL may be due to molecular characteristics of this race. 相似文献
6.
de Castro Heizir F. Napoleão Diovana A. S. Oliveira Pedro C. 《Applied biochemistry and biotechnology》1998,(1):667-675
Several reports exist in the literature citing the decrease in conversion rates of organic-phase catalytic synthesis reactions
when acetic acid is present as a reaction component. This inhibition is thought to result from damage to either the hydration
layer-protein interaction or the overall enzyme structure. In this work, the inhibitory effect of acetic acid on lipase enzyme
activity was ameliorated by conducting syntheses under acetic acid-limiting conditions in a fed-batch system, resulting in
higher product yields. Periodic additions of acetic acid at levels of 40 mM or less gave maximum yields of 65% conversion for the reaction of citronellol and acetic acid to form citronellyl acetate.
The enzyme used was a fungal lipase fromMucor miehei, and was immobilized on macroporous synthetic resin (a Novo lipozyme Novo Nordisk, Denmark). These results represent a fourfold
improvement over batch runs reported in the literature for direct esterification of terpene alcohol with acetic acid using
lipozyme as a catalytic agent. 相似文献
1