Manuel Roig
University of Salamanca, Physical Chemistry, Faculty Member
- Dr Manuel Garcia Roig is professor of Physical Chemistry, leader of the research group Biocatalysis and Biotechnology... moreDr Manuel Garcia Roig is professor of Physical Chemistry, leader of the research group Biocatalysis and Biotechnology and director of the Center for Research and Technological Development of Water (CIDTA) of the University of Salamanca in Spain. After obtaining his PhD in 1981, he became a postdoctoral research fellow at Harvard University (1981-83) and visiting research fellow at different universities of UK and Czech Republic, carrying out basic and applied research on microheterogeneous and heterogeneous biocatalysis.edit
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Research Interests: Materials Science, Crystallization, Medicine, Biological Sciences, Humans, and 15 moreMathematical Sciences, Escherichia coli, Campylobacter, Birds, Animals, Arecaceae, Glycosylation, CHEMICAL SCIENCES, Enterococcus faecium, Acinetobacter baumannii, Amino Acid Sequence, Cytotoxins, Biochemistry and cell biology, Dimerization, and Adenosine Triphosphate
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Low angle laser light scattering (LALLS) and multi-angle laser light scattering (MALLS) methods have become valuable, if not indispensable, tools for the chemist and biochemist, since they can be used to determine the absolute molecular... more
Low angle laser light scattering (LALLS) and multi-angle laser light scattering (MALLS) methods have become valuable, if not indispensable, tools for the chemist and biochemist, since they can be used to determine the absolute molecular weight and size of molecules in solution. When linked to a gel permeation chromatography system, they become even more powerful tools, providing information on molecular weight averages and their distributions (polydispersity). LALLS has essenttially been superseded by the development of on-line MALLS and size-exclusion chromatography (SEC)/MALLS systems, which have facilitated the greater application of light scattering theory in structure elucidation. For example, the determination of root mean square radii, molecular conformation and structure, branching ratios etc., are now readily achievable. This paper reviews the “theoretical backbone” of light scattering methods and the technology available for use in this particular aspect of macromolecular characterisation. Particular emphasis is placed on the use of SEC/MALLS and SEC/LALLS for the molecular weight elucidation of polysaccharides (such as carrageenans, starch, hyaluronic acid and dextrans), proteins, and the examination of branching in large macromolecular structures
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Domain III (DIII) of the tick-borne encephalitis virus (TBEV) protein E contains epitopes, which induce antibodies capable of neutralizing the virus. To enhance the immunogenicity of this protein, which has a low molecular weight, the aim... more
Domain III (DIII) of the tick-borne encephalitis virus (TBEV) protein E contains epitopes, which induce antibodies capable of neutralizing the virus. To enhance the immunogenicity of this protein, which has a low molecular weight, the aim of the present work was to express, isolate, and characterize a chimeric protein based on the fusion of the bacterial chaperone HSP70 of Yersinia pseudotuberculosis and EIII (DIII + stem) as a prospective antigen for an adjuvanted delivery system, the tubular immunostimulating complex (TI-complex). The chimeric construction was obtained using pET-40b(+) vector by ligating the respective genes. The resulting plasmid was transformed into DE3 cells for the heterologous expression of the chimeric protein, which was purified by immobilized metal affinity chromatography (IMAC). ELISA, differential scanning calorimetry, intrinsic fluorescence, and computational analysis were applied for the characterization of the immunogenicity and conformation of the ch...
Research Interests: Chemistry, Biology, Virology, Medicine, Biomolecules, and 3 moreFusion Protein, Immunogenicity, and Antigen
This work was partially supported by project SA052A10-2, funded by Consejeria de Educacion de la Junta de Castilla y Leon (Spain).
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Research Interests: Engineering and Impact
The Water Framework Directive (WFD, EC, 2000) states that the “good” ecological status of natural water bodies must be based on their chemical, hydromorphological and biological features, especially under drastic conditions of floods or... more
The Water Framework Directive (WFD, EC, 2000) states that the “good” ecological status of natural water bodies must be based on their chemical, hydromorphological and biological features, especially under drastic conditions of floods or droughts. Phytoplankton is considered a good environmental bioindicator (WFD) and climate change has a strong impact on phytoplankton communities and water quality. The development of robust techniques to predict and control phytoplankton growth is still in progress. The aim of this study is to analyze the impact of the different stressors associated with the change in phytoplanktonic communities in small rivers in the center of the Iberian Peninsula (Southwestern Europe). A statistical study on the identification of the essential limiting variables in the phytoplankton growth and its seasonal variation by climate change was carried out. In this study, a new method based on the partial least-squares (PLS) regression technique has been used to predict...
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Plant peroxidases are presently used extensively in a wide range of biotechnological applications owing to their high environmental and thermal stability. As part of efforts towards the discovery of appealing new biotechnological enzymes,... more
Plant peroxidases are presently used extensively in a wide range of biotechnological applications owing to their high environmental and thermal stability. As part of efforts towards the discovery of appealing new biotechnological enzymes, the peroxidase from leaves of the palm tree Chamaerops excelsa (CEP) was extracted, purified and crystallized in its native form. An X-ray diffraction data set was collected at a synchrotron source and data analysis showed that the CEP crystals belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 70.2, b = 100.7, c = 132.3 Å.
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A Gram-positive, aerobic, long-rod-shaped, non-spore-forming bacterium (strain PPLBT) was isolated from soil mixed with Iberian pig hair. This actinomycete showed keratinase activity in vitro when chicken feathers were added to the... more
A Gram-positive, aerobic, long-rod-shaped, non-spore-forming bacterium (strain PPLBT) was isolated from soil mixed with Iberian pig hair. This actinomycete showed keratinase activity in vitro when chicken feathers were added to the culture medium. Strain PPLBT was oxidase-negative and catalase-positive and produced lipase and esterase lipase. This actinomycete grew at 40 °C on nutrient agar and in the same medium containing 5 % (w/v) NaCl. Growth was observed with many different carbohydrates as the sole carbon source. On the basis of 16S rRNA gene sequence similarity, strain PPLBT was shown to belong to the genus Terrabacter of the family Intrasporangiaceae. Strain PPLBT showed 98·8 % 16S rRNA gene sequence similarity to Terrabacter tumescens. Chemotaxonomic data, such as the main ubiquinone (MK-8), the main polar lipids (phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylinositol) and the main fatty acids (i-C15 : 0, ai-C15 : 0, i-C16 : 0 and ai-C17 : 0) supported th...
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Acceso de usuarios registrados. Acceso de usuarios registrados Usuario Contraseña. ...
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In plants, adverse conditions often induce an increase in reactive oxygen species (ROS) such as hydrogen peroxide (H2O2). H2O2 is reduced to water, and thus becomes detoxified by enzymes such as Cytisus multiflorus peroxidase (CMP). Here,... more
In plants, adverse conditions often induce an increase in reactive oxygen species (ROS) such as hydrogen peroxide (H2O2). H2O2 is reduced to water, and thus becomes detoxified by enzymes such as Cytisus multiflorus peroxidase (CMP). Here, the steady-state kinetics of the H2O2-supported oxidation of different organic substrates by CMP was investigated. Analysis of the initial rates vs. H2O2 and reducing substrate concentrations proved to be consistent with a substrate-inhibited Ping-Pong Bi-Bi reaction mechanism. The phenomenological approach expresses the peroxidase Ping-Pong mechanism in the form of the Michaelis-Menten equation and affords an interpretation of the effects in terms of the kinetic parameters [Formula: see text] , [Formula: see text] , kcat, [Formula: see text] , [Formula: see text] and of the microscopic rate constants, k1 and k3, of the shared three-step catalytic cycle of peroxidases.
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Suicide inactivation is a common mechanism observed for haem peroxidases, in which the enzyme is inactivated as a result of self-oxidation mediated by intermediate highly oxidizing enzyme forms during the catalytic cycle. The... more
Suicide inactivation is a common mechanism observed for haem peroxidases, in which the enzyme is inactivated as a result of self-oxidation mediated by intermediate highly oxidizing enzyme forms during the catalytic cycle. The time-dependence and the inactivation mechanism of Cytisus multiflorus peroxidase (CMP) by hydrogen peroxide were studied kinetically with four co-substrates (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), ferulic acid, guaiacol and o-dianisidine). Catalytic activity decreased following the sequence ABTS>guaiacol>ferulic acid>o-dianisidine. Once the intermediate complex (compound III-H2O2) had been formed, competition was established between the catalytic pathway and the suicide inactivation pathway. One mole of CMP afforded around 3790 turnovers of H2O2 for ABTS before its complete inactivation. These results suggest that CMP follows a suicide mechanism, the enzyme not being protected in this case. The mechanism of suicide inactiva...
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... John F. Kennedy Research Laboratory for the Chemistry of Bioactive Carbohydrates and Proteins, School of Chemistry, Birmingham University, PO Box 363, Birmingham 815 2lT, UK ... They showed that the kinetics parameters kat and K, were... more
... John F. Kennedy Research Laboratory for the Chemistry of Bioactive Carbohydrates and Proteins, School of Chemistry, Birmingham University, PO Box 363, Birmingham 815 2lT, UK ... They showed that the kinetics parameters kat and K, were altered little in the reverse mi-celle. ...
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This article reviews the strategies and successes of modifying enzymes by means of biophysicochemical transformations. By judicious choice of methods, it has been possible to modify enzymes through physical interactions, chemical... more
This article reviews the strategies and successes of modifying enzymes by means of biophysicochemical transformations. By judicious choice of methods, it has been possible to modify enzymes through physical interactions, chemical reactions and/or mutagenesis to alter a very wide range of properties ranging from stability and solubility on the one hand to catalytic activity and selectivity on the other.
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... crustáceos) M. García Roig, FI Ramírez Paredes y T. Manzano Muñoz Dpto. ... La pluma de pollo es una intrin-cada red de fibras de queratina es-tables e insolubles en agua con ele-vada área superficial y es también un abundante... more
... crustáceos) M. García Roig, FI Ramírez Paredes y T. Manzano Muñoz Dpto. ... La pluma de pollo es una intrin-cada red de fibras de queratina es-tables e insolubles en agua con ele-vada área superficial y es también un abundante biorresiduo. Suyama y col. ...
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Acceso de usuarios registrados. Acceso de usuarios registrados Usuario Contraseña. ...
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Acceso de usuarios registrados. Acceso de usuarios registrados Usuario Contraseña. ...
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ABSTRACT The covalent immobilization of α-amylase on new isocyanate, acid chloride and carboxylic acid-activated plastic supports shows the viability of such supports for immobilizing enzymes, specially those reacting with 1,... more
ABSTRACT The covalent immobilization of α-amylase on new isocyanate, acid chloride and carboxylic acid-activated plastic supports shows the viability of such supports for immobilizing enzymes, specially those reacting with 1, 6-diaminohexane and glutaraldehyde for producing side arms. The operational stability of immobilized α-amylase could be extended by crosslinking the enzyme or by extending the support's side arm (substrate concentration has no effect). Inactive immobilized α-amylase were unfolded and then refolded at elevated temperature, these supports were found to be essential in increasing the stability of the enzyme during refolding. The pH curves for the immobilized enzyme were in general found not to be shifted from the soluble enzyme's pH optimum, although one isocyanate plastic support derivative shifted the pH activity profile of α-amylase to a higher range by 1.5 pH units, probably due to reaction between the enzyme and the free anhydride groups existing on the support's surface. In all cases, the immobilized enzyme's temperature activity profiles were shifted to a lower temperature range when compared to the soluble enzyme. The immobilized α-amylase Michaelis constants increased and the the maximum rates and specific activities decreased when compared to the soluble enzyme kinetic parameters.
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... crustáceos) M. García Roig, FI Ramírez Paredes y T. Manzano Muñoz Dpto. ... La pluma de pollo es una intrin-cada red de fibras de queratina es-tables e insolubles en agua con ele-vada área superficial y es también un abundante... more
... crustáceos) M. García Roig, FI Ramírez Paredes y T. Manzano Muñoz Dpto. ... La pluma de pollo es una intrin-cada red de fibras de queratina es-tables e insolubles en agua con ele-vada área superficial y es también un abundante biorresiduo. Suyama y col. ...
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By a simple oversight, an immobilisation membrane was inserted into the holding apparatus without removal of the transit packing foam. This foam was ultimately proved to be as effective an immobilisation agent as the real membrane.
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Methods for the covalent immobilization of alpha-amylase and glucoamylase on to epoxide-, isocyanate-, acid chloride-, and carboxylic acid-activated plastic supports have been optimized. The effects of the following parameters have been... more
Methods for the covalent immobilization of alpha-amylase and glucoamylase on to epoxide-, isocyanate-, acid chloride-, and carboxylic acid-activated plastic supports have been optimized. The effects of the following parameters have been examined: coupling time, pH, and temperature; availability of the free essential reacting groups on the supports; porosity of the supports; and enzyme loading. Properties of the immobilized enzymes, such as coupled activity and operational stability were assessed.
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ABSTRACT Human placental alkaline phosphatase has been chemically immobilized on a hydrophilic cross-flow microfiltration membrane made of polyvinylidene difluoride (PVDF) chemically labelled with 1-carbonylimidazole groups.... more
ABSTRACT Human placental alkaline phosphatase has been chemically immobilized on a hydrophilic cross-flow microfiltration membrane made of polyvinylidene difluoride (PVDF) chemically labelled with 1-carbonylimidazole groups. Physicochemical characterization of this immobilized biocatalyst focused especially on attributes such as the immobilization isotherms (Langmuir type) of the enzyme to the support, the stability of the catalytic activity, the effects of pH and temperature on this activity and the existence of limitations of external diffusion for H+, substrate and/or products. Regarding enzyme stability and its dependence on different experimental conditions, patterns of hysteresis or memory are proposed.
The covalent immobilization of alpha-amylase on new isocyanate, acid chloride and carboxylic acid--activated plastic supports shows the viability of such supports for immobilizing enzymes, especially those reacting with 1,6-diaminohexane... more
The covalent immobilization of alpha-amylase on new isocyanate, acid chloride and carboxylic acid--activated plastic supports shows the viability of such supports for immobilizing enzymes, especially those reacting with 1,6-diaminohexane and glutaraldehyde for producing side arms. The operational stability of immobilized alpha-amylase could be extended by crosslinking the enzyme or by extending the support's side arm (substrate concentration has no effect). Inactive immobilized alpha-amylase were unfolded and then refolded at elevated temperature, these supports were found to be essential in increasing the stability of the enzyme during refolding. The pH curves for the immobilized enzyme were in general found not to be shifted from the soluble enzyme's pH optimum, although one isocyanate plastic support derivative shifted the pH activity profile of alpha-amylase to a higher range by 1.5 pH units, probably due to reaction between the enzyme and the free anhydride groups exist...
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... Br. J. Hue mat. 16,353361. FURIE B. FURIE B. (1979) The role of metal ions in blood coagulation. ... Srand. J. Haemal. 3, 342. GODAL H. C ABILDGAARD U. KIERULF P. (1971) Etha nol gelation and fibrin monomers in plasma. Srand. J.... more
... Br. J. Hue mat. 16,353361. FURIE B. FURIE B. (1979) The role of metal ions in blood coagulation. ... Srand. J. Haemal. 3, 342. GODAL H. C ABILDGAARD U. KIERULF P. (1971) Etha nol gelation and fibrin monomers in plasma. Srand. J. Haemal. 13 (Suppl.), 189191. ...
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1. A study has been carried out on the steady-state kinetics followed by the alkaline phosphatase from Escherichia coli at different pH, temperatures, ionic strengths, phosphate concentrations and in the presence of the effectors such as... more
1. A study has been carried out on the steady-state kinetics followed by the alkaline phosphatase from Escherichia coli at different pH, temperatures, ionic strengths, phosphate concentrations and in the presence of the effectors such as Tris, NH4+--NH3 and CH3OH; p-nitrophenyl phosphate was used as substrate. 2. Contrary to what has generally been accepted, in most cases the enzyme follows non-Michaelian kinetics for a wide substrate concentration range, giving concave-down Lineweaver-Burk plots. Only at high phosphate concentrations (5 . 10(-3) M) and at high ionic strengths (2.0 M) is a linear Lineweaver-Burk plot obtained (Michaelian kinetics). 3. In order to analyse the kind of kinetics obtained, a non-linear regression fitting method was used to obtain rate vs substrate concentration equations as polynomial quotients of minimum degree with positive coefficients. 4. Most of the data obtained follows 2:2 degree type equations. 5. These results tend to suggest an idea of cooperat...
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An HPLC method using a reversed-phase macroreticular PLRP-S column and phosphate buffer as eluent is described for the analysis of L-ascorbic acid degradation products, 5-hydroxymethyl furfuraldehyde and furfuraldehyde, in processed fruit... more
An HPLC method using a reversed-phase macroreticular PLRP-S column and phosphate buffer as eluent is described for the analysis of L-ascorbic acid degradation products, 5-hydroxymethyl furfuraldehyde and furfuraldehyde, in processed fruit juices. Measurement of the levels of 5-HMF and furfuraldehyde in citrus juices against time showed the presence of 5-HMF (0.45 mg l-1) even at zero time. An assessment on the effect of the additives on the formation of 5-HMF of reconstituted single-strength orange juice showed virtually the same results for all the samples stored at 4 degrees C and 20 degrees C, irrespective of the additive. For citrus juice samples which had been subjected to accelerated degradation, those that showed the highest decomposition of L-ascorbic acid, produced the highest level of 5-HMF. The presence of furfuraldehyde in any of the samples was not detected, probably due to the fact that furfuraldehyde was formed in such small amounts which are below the minimum detecta...
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The approaching formaüon of a single€uropean market should be a matler of ;erious reflection for managers of both irdust¡ies and public and private :rsearch centres around EC counfies. ln the new and nu.¡dr more competitive ¿¡rcumstances... more
The approaching formaüon of a single€uropean market should be a matler of ;erious reflection for managers of both irdust¡ies and public and private :rsearch centres around EC counfies. ln the new and nu.¡dr more competitive ¿¡rcumstances of a single markel indusfies will have to ¡esfucture üeir stralegy @nceming researcfr ard developmenL The seardr for nevy forms of cmperaüon between univeaities and indusüies becoñEs urgent during this process of adaptation. Eiotectrnology ofiers an appropriale framework for establishing lhese new forms of cooperation. This irjea is based on two faAors: the intiinsic chüacteristics of biotechnological processes and the hi¡h quality of European research leams in this field. lmportant advances made recendy ín Enzymology and Genetic Engineering are certrin to fofllent the beneficial exploitatión of -' enzymes and cells in o¡der to cary out very specifc bbtrarsbrmaüons. which will undoubtedly be ol servbe lo s€ctors dealing wilh areas such as Chemis...
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Plant peroxidases are presently used extensively in a wide range of biotechnological applications owing to their high environmental and thermal stability. As part of efforts towards the discovery of appealing new biotechnological enzymes,... more
Plant peroxidases are presently used extensively in a wide range of biotechnological applications owing to their high environmental and thermal stability. As part of efforts towards the discovery of appealing new biotechnological enzymes, the peroxidase from leaves of the palm tree Chamaerops excelsa (CEP) was extracted, purified and crystallized in its native form. An X-ray diffraction data set was collected at a synchrotron source and data analysis showed that the CEP crystals belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 70.2, b = 100.7, c = 132.3 Å.
ABSTRACT Pseudomonas strains C12B and A3 were separately immobilised in polyurethane foam and their ability to biodegrade n-decane or n-hexadecane tested and compared with that of freely suspended cells. In the presence of immobilised... more
ABSTRACT Pseudomonas strains C12B and A3 were separately immobilised in polyurethane foam and their ability to biodegrade n-decane or n-hexadecane tested and compared with that of freely suspended cells. In the presence of immobilised Pseudomonas C12B or A3 cells about 90% of n-alkane, originally present in liquid medium, was removed, 25%-40% of which was due to biodegradation.
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ABSTRACT This study reports a procedure for the evaluation and comparison of the adsorption and filtration capacities of commercial activated carbons in the treatment of drinking water and the design and operation of a pilot plant to... more
ABSTRACT This study reports a procedure for the evaluation and comparison of the adsorption and filtration capacities of commercial activated carbons in the treatment of drinking water and the design and operation of a pilot plant to simulate the behavior of fast open filters made of granular activated carbon. The milestone of this experimental work was to determine the adsorption and filtration capacities and the physicochemical properties of five commercial activated carbons with a view to determining which activated carbon might replace the open sand filters of the drinking water treatment plant (DWTP) of the city of Salamanca (western Spain). Compliance with the requirements and physicochemical characteristics stipulated in the EN 12915 European standard for the different activated carbons tested was analyzed, and studies of the prewashing and behavior of the carbons operating in the filters were performed. In this sense, filtration tests to study the saturation of the bed, the variations in pressure drop and the performance of the removal of organic matter in suspension were carried out. Furthermore, the optimal time and rate of the countercurrent washing of the filters and the expansion of the filter bed were evaluated. In the adsorption assays, the specific surface area, porosity, useful lifetime and capacity of adsorption of the dissolved organic matter especially humic acids, the major precursors of water chlorination by-products - of the activated carbons were determined. The results not only provided an overview of the actual behavior of different types of commercial activated carbons from their initial installation up to the end of their useful life, but also permitted optimization of the filtration and adsorption processes that could lead to the corresponding economic savings and energy reduction in the use of such activated carbon filter-adsorbers.
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Palm tree peroxidases are known to be very stable enzymes and the peroxidase from the Chamaerops excelsa (CEP), which has a high pH and thermal stability, is no exception. To date, the structural and molecular events underscoring such... more
Palm tree peroxidases are known to be very stable enzymes and the peroxidase from the Chamaerops excelsa (CEP), which has a high pH and thermal stability, is no exception. To date, the structural and molecular events underscoring such biochemical behavior have not been explored in depth. In order to identify the structural characteristics accounting for the high stability of palm tree peroxidases, we solved and refined the X-ray structure of native CEP at a resolution of 2.6 Å. The CEP structure has an overall fold typical of plant peroxidases and confirmed the conservation of characteristic structural elements such as the heme group and calcium ions. At the same time the structure revealed important modifications in the amino acid residues in the vicinity of the exposed heme edge region, involved in substrate binding, that could account for the morphological variations among palm tree peroxidases through the disruption of molecular interactions at the second binding site. These modifications could alleviate the inhibition of enzymatic activity caused by molecular interactions at the latter binding site. Comparing the CEP crystallographic model described here with other publicly available peroxidase structures allowed the identification of a noncovalent homodimer assembly held together by a number of ionic and hydrophobic interactions. We demonstrate, that this dimeric arrangement results in a more stable protein quaternary structure through stabilization of the regions that are highly dynamic in other peroxidases. In addition, we resolved five N-glycosylation sites, which might also contribute to enzyme stability and resistance against proteolytic cleavage.