Rosa María Ferraz

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BACKGROUND Many enzymes of industrial interest are not in the market since they are bio-produced as bacterial inclusion bodies, believed to be biologically inert aggregates of insoluble protein. RESULTS By using two structurally and functionally different model enzymes and two fluorescent proteins we show that physiological aggregation in bacteria might(More)
The quantitative detection of low analyte concentrations in complex samples is becoming an urgent need in biomedical, food and environmental fields. Biosensors, being hybrid devices composed by a biological receptor and a signal transducer, represent valuable alternatives to non biological analytical instruments because of the high specificity of the(More)
Recombinant beta-galactosidases accommodating one or two different peptides from the foot-and-mouth disease virus (FMDV) nonstructural protein 3B per enzyme monomer showed a drastic enzymatic activity reduction, which mainly affected proteins with double insertions. Recombinant beta-galactosidases were enzymatically reactivated by 3B-specific murine(More)
The impact of antibodies on the target's epitope conformation is a major determinant of HIV-1 neutralization and a potential contributor to disease progression. We explore here a conformation-sensitive enzymatic nanosensor for the high-throughput functional screening of human anti-HIV-1 antibodies in sera. When displaying a model epitope from a gp41(More)
We have explored the effect of antiretroviral drugs on the antiviral immune response in human immunodeficiency virus-1 (HIV-1)-infected patients by using an enzymatic immunosensor that detects epitope-modifying anti-gp41 antibodies. By this molecular sensing approach, we have identified an irreversible impact of drug administration on the functionality of(More)
Among protein biosensors, those based on enzymatic responses to specific analytes offer convenient instruments for fast and ultra-fast molecular diagnosis, through the comparative analysis of the product formed in presence and in absence of the effector. We have explored here the performance of five beta-galactosidase substrates during the activation of a(More)
Escherichia coli beta-galactosidase responds enzymatically to antiviral antibodies when a viral antigenic peptide, acting as receptor, is conveniently displayed in the vicinity of the active site. The allosteric response of a beta-galactosidase molecular sensor containing a B-cell epitope from HIV has been finely dissected upon binding of an effector(More)
We have analyzed the suitability of six antigenic peptides from several HIV-1 structural proteins (namely gp41, gp120, p17, and p24), as anti-HIV-1 antibody receptors in an allosteric enzymatic biosensor. These peptides were inserted in a solvent-exposed surface of Escherichia coli (E. coli) beta-galactosidase by means of conventional recombinant DNA(More)
Fuculose-1-phosphate aldolase (FucA) has been produced in Escherichia coli as active inclusion bodies (IBs) in batch cultures. The activity of insoluble FucA has been modulated by a proper selection of producing strain, culture media, and process conditions. In some cases, when an optimized defined medium was used, FucA IBs were more active (in terms of(More)
Here a novel electrochemical method for the rapid detection of anti-HIV antibodies in serum is presented. The novelty lies in the combination of allosteric enzymes and coulometry to yield a fast, simple and reliable HIV diagnostic method. We have used a previously developed beta-galactosidase enzyme that is efficiently activated by anti-HIV antibodies(More)
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