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Durán-Gutiérrez DP, López-Hidalgo M, Peña-Gomar IM, Zamorano-Carrillo A, Gómez-Esquivel ML, Castrejón-Flores JL, Reyes-López CA. Molecular docking analysis of a dermatan sulfate tetra-saccharide to human alpha-L-iduronidase. Bioinformation 2023; 19:1116-1123. [PMID: 38250526 PMCID: PMC10794756 DOI: 10.6026/973206300191116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 12/31/2023] [Accepted: 12/31/2023] [Indexed: 01/23/2024] Open
Abstract
Human alpha-L-iduronidase (IDUA) is a 653 amino acid protein involved in the sequential degradation of glycos-amino-glycans (GAG), heparan sulfate (HS), and dermatan sulfate (DS). Some variants in the IDUA gene produce a deficient enzyme that causes un-degraded DS and HS to accumulate in multiple tissues, leading to an organ dysfunction known as muco-poly-saccharidosis type I (MPS I). Molecular and catalytic activity assays of new or rare variants of IDUA do not predict the phenotype that a patient will develop. Therefore, it is of interest to describe the molecular docking analysis, to locate binding regions of DS to IDUA to better understand the effect of a variant on MPS I development. The results presented herein demonstrate the presence of a polar/acidic catalytic site and a basic region in the putative binding site of DS to IDUA. Further, synthetic substrate docking with the enzyme could help in the predictions of the MPS I phenotype.
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Affiliation(s)
- Darinka P Durán-Gutiérrez
- Sección de Estudios de Posgrado e Investigación, ENMyH, Instituto Politécnico Nacional, Guillermo Massieu Helguera, No. 239, Fracc. "La Escalera", Ticomán, C.P. 07320, Mexico City, Mexico
| | - Marisol López-Hidalgo
- Sección de Estudios de Posgrado e Investigación, ENMyH, Instituto Politécnico Nacional, Guillermo Massieu Helguera, No. 239, Fracc. "La Escalera", Ticomán, C.P. 07320, Mexico City, Mexico
| | - Iliana M Peña-Gomar
- Departamento de Genética, Hospital IMSS-Bienestar Cuajimalpa, Cuajimalpa de Morelos, Mexico City, Mexico
| | - Absalom Zamorano-Carrillo
- Sección de Estudios de Posgrado e Investigación, ENMyH, Instituto Politécnico Nacional, Guillermo Massieu Helguera, No. 239, Fracc. "La Escalera", Ticomán, C.P. 07320, Mexico City, Mexico
| | - Mónica L Gómez-Esquivel
- Sección de Estudios de Posgrado e Investigación, ENMyH, Instituto Politécnico Nacional, Guillermo Massieu Helguera, No. 239, Fracc. "La Escalera", Ticomán, C.P. 07320, Mexico City, Mexico
| | - José L Castrejón-Flores
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, Gustavo A. Madero, Mexico City, Mexico
| | - César A Reyes-López
- Sección de Estudios de Posgrado e Investigación, ENMyH, Instituto Politécnico Nacional, Guillermo Massieu Helguera, No. 239, Fracc. "La Escalera", Ticomán, C.P. 07320, Mexico City, Mexico
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Bello F, Orozco E, Benítez-Cardoza CG, Zamorano-Carrillo A, Reyes-López CA, Pérez-Ishiwara DG, Gómez-García C. The novel EhHSTF7 transcription factor displays an oligomer state and recognizes a heat shock element in the Entamoeba histolytica parasite. Microb Pathog 2021; 162:105349. [PMID: 34864144 DOI: 10.1016/j.micpath.2021.105349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 12/01/2021] [Accepted: 12/01/2021] [Indexed: 01/09/2023]
Abstract
The heat shock response is a conserved mechanism that allows cells to respond and survive stress damage and is transcriptionally regulated by the heat shock factors and heat shock elements. The P-glycoprotein confer the multidrug resistance phenotype; Entamoeba histolytica has the largest multidrug resistance gene family described so far; one of these genes, the EhPgp5 gene, has an emetine-inducible expression. A functional heat shock element was localized in the EhPgp5 gene promoter, indicating transcriptional regulation by heat shock factors. In this work, we determined the oligomer state of EhHSTF7 and the recognition of the heat shock element of the EhPgp5 gene. The EhHSTF7 recombinant protein was obtained as monomer and oligomer. In silico molecular docking predicts protein-DNA binding between EhHSTF7 and 5'-GAA-3' complementary bases. The rEhHSTF7 protein specifically binds to the heat shock element of the EhPgp5 gene in gel shift assays. The competition assays with heat shock element mutants indicate that 5'-GAA-3' complementary bases are necessary for the rEhHSTF7 binding. Finally, the siRNA-mediated knockdown of Ehhstf7 expression causes downregulation of EhPgp5 expression, suggesting that EhHSTF7 is likely to play a key role in the E. histolytica multidrug resistance. This is the first report of a transcription factor that recognizes a heat shock element from a gene involved in drug resistance in parasites. However, further analysis needs to demonstrate the biological relevance of the EhHSTF7 and the rest of the heat shock factors of E. histolytica, to understand the underlying regulation of transcriptional control in response to stress.
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Affiliation(s)
- Fabiola Bello
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Instituto Politécnico Nacional 2508, San Pedro Zacatenco, Gustavo A. Madero, 07360, Mexico City, Mexico
| | - Esther Orozco
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Instituto Politécnico Nacional 2508, San Pedro Zacatenco, Gustavo A. Madero, 07360, Mexico City, Mexico
| | - Claudia G Benítez-Cardoza
- Programa Institucional en Biomedicina Molecular, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Guillermo Massieu Helguera 239, La Escalera, Gustavo A. Madero, 07320, Mexico City, Mexico
| | - Absalom Zamorano-Carrillo
- Programa Institucional en Biomedicina Molecular, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Guillermo Massieu Helguera 239, La Escalera, Gustavo A. Madero, 07320, Mexico City, Mexico
| | - César A Reyes-López
- Programa Institucional en Biomedicina Molecular, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Guillermo Massieu Helguera 239, La Escalera, Gustavo A. Madero, 07320, Mexico City, Mexico
| | - D Guillermo Pérez-Ishiwara
- Programa Institucional en Biomedicina Molecular, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Guillermo Massieu Helguera 239, La Escalera, Gustavo A. Madero, 07320, Mexico City, Mexico
| | - Consuelo Gómez-García
- Programa Institucional en Biomedicina Molecular, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Guillermo Massieu Helguera 239, La Escalera, Gustavo A. Madero, 07320, Mexico City, Mexico.
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Michicotl-Meneses MM, Thompson-Bonilla MDR, Reyes-López CA, García-Pérez BE, López-Tenorio II, Ordaz-Pichardo C, Jaramillo-Flores ME. Inflammation Markers in Adipose Tissue and Cardiovascular Risk Reduction by Pomegranate Juice in Obesity Induced by a Hypercaloric Diet in Wistar Rats. Nutrients 2021; 13:2577. [PMID: 34444736 PMCID: PMC8402035 DOI: 10.3390/nu13082577] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/22/2021] [Accepted: 07/25/2021] [Indexed: 02/07/2023] Open
Abstract
Pomegranate juice (Punica granatum) has been used since ancient times in traditional medicine (Unani Medicine, Ayurveda); its main compounds are anthocyanins and ellagic acid, which have anti-inflammatory, antioxidant, hepatoprotective, and cardiovascular health effects. The objective was to evaluate the effect of pomegranate juice on inflammation, blood pressure, and vascular and physiological markers associated with obesity induced by a high-fat diet in a murine model. The results show that pomegranate juice reduces the concentration of low-density lipoprotein cholesterol (cLDL) 39% and increases the concentration of high-density lipoprotein cholesterol (cHDL) by 27%, leading to a 12%-18% decrease in the risk of cardiovascular diseases (CVD). In addition to reducing blood pressure by 24%, it also had an antiatherogenic effect by decreasing sE-selectin levels by 42%. On the other hand, the juice significantly increased adiponectin levels in adipose tissue, decreased levels of inflammation markers (tumor necrosis factor-α (TNF-α), plasminogen activator inhibitor-1 (PAI-1), interleukin-17A (IL-17A), interleukin-6 (IL-6), interleukin-1β (IL-1β)), and inhibited the monocyte chemoattractant protein-1 (MCP-1). Pomegranate juice requires clinical studies to prove its immunoregulatory and therapeutic effects on cardiovascular and atherogenic risks.
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Affiliation(s)
- Maria Monica Michicotl-Meneses
- Departamento de Ingeniería Bioquímica, Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Mexico City 07738, Mexico; (M.M.M.-M.); (I.I.L.-T.)
| | - María del Rocío Thompson-Bonilla
- Laboratorio de Medicina Genómica, Investigación Biomédica y Traslacional, ISSSTE, Hospital Regional “1° de Octubre”, Mexico City 07760, Mexico;
| | - César A. Reyes-López
- Laboratorio de Bioquímica Estructural, Instituto Politécnico Nacional, Escuela Nacional de Medicina y Homeopatía, Mexico City 07320, Mexico;
| | - Blanca Estela García-Pérez
- Laboratorio de Microbiología General, Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Mexico City 11340, Mexico;
| | - Itzel I. López-Tenorio
- Departamento de Ingeniería Bioquímica, Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Mexico City 07738, Mexico; (M.M.M.-M.); (I.I.L.-T.)
| | - Cynthia Ordaz-Pichardo
- Laboratorio de Biología Celular y Productos Naturales, Instituto Politécnico Nacional, Escuela Nacional de Medicina y Homeopatía, Mexico City 07320, Mexico;
| | - María Eugenia Jaramillo-Flores
- Departamento de Ingeniería Bioquímica, Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Mexico City 07738, Mexico; (M.M.M.-M.); (I.I.L.-T.)
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Gómez-Esquivel ML, Guidos-Fogelbach GA, Rojo-Gutiérrez MI, Mellado-Abrego J, Bermejo-Guevara MA, Castillo-Narváez G, Velázquez-Sámano G, Velasco-Medina AA, Moya-Almonte MG, Vallejos-Pereira CM, López-Hidalgo M, Godínez-Victoria M, Reyes-López CA. Identification of an allergenic calmodulin from Amaranthus palmeri pollen. Mol Immunol 2021; 132:150-156. [PMID: 33592570 DOI: 10.1016/j.molimm.2021.01.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 01/05/2021] [Accepted: 01/30/2021] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Pollens are an important source of allergens that trigger rhinitis or asthma. The allergenic extracts of pollens used to diagnose and treat allergies contain different allergenic antigens. Isolated allergenic proteins are employed in in vitro assays, skin tests and allergenic-specific immunotherapy. Calcium-binding allergens are clinically relevant antigens, and their allergenicity can be affected by Ca2+ binding. In this work, a calmodulin was identified as an allergen from Amaranthus palmeri pollen, an important source of pollinosis in Europe, Asia and North America. MATERIALS AND METHODS Allergenic calmodulin from A. palmeri pollen was isolated by size-exclusion chromatography and reverse-phase chromatography and identified by mass spectrometry. Sensitization to isolated calmodulin was evaluated by skin prick tests in patients with allergy to A. palmeri pollen. RESULTS Size-exclusion chromatography yielded two fractions that were recognized by the IgE of patients allergic to A. palmeri pollen. Mass spectrometry analysis of the fractions from reverse-phase chromatography showed peptide sequences that identified a calmodulin. Skin prick tests showed that the isolated calmodulin was recognized by 56% of patients allergic to A. palmeri pollen. CONCLUSION A. palmeri pollen calmodulin could be a clinically relevant allergen in patients sensitized to this source.
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Affiliation(s)
- Mónica Luz Gómez-Esquivel
- Sección De Estudios De Posgrado e Investigación, ESM, Instituto Politécnico Nacional, Plan De San Luis y Díaz Mirón s/n, Col. Casco De Santo Tomas, Alcaldía Miguel Hidalgo, C.P. 11340, Ciudad De México, Mexico; Sección de Estudios de Posgrado e Investigación, ENMH, Instituto Politécnico Nacional, Guillermo Massieu Helguera No. 239, Col. Frac. "La Escalera", Ticomán, Gustavo A. Madero, C.P. 07320, Ciudad De México, Mexico
| | - Guillermo Arturo Guidos-Fogelbach
- Sección de Estudios de Posgrado e Investigación, ENMH, Instituto Politécnico Nacional, Guillermo Massieu Helguera No. 239, Col. Frac. "La Escalera", Ticomán, Gustavo A. Madero, C.P. 07320, Ciudad De México, Mexico
| | - María Isabel Rojo-Gutiérrez
- Servicio de Alergia e Inmunología, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Col. Magdalena De Las Salinas, Gustavo A. Madero, C.P. 07760, Ciudad De México, Mexico
| | - Jaime Mellado-Abrego
- Servicio de Alergia e Inmunología, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Col. Magdalena De Las Salinas, Gustavo A. Madero, C.P. 07760, Ciudad De México, Mexico
| | - Mario Alberto Bermejo-Guevara
- Servicio de Alergia e Inmunología, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Col. Magdalena De Las Salinas, Gustavo A. Madero, C.P. 07760, Ciudad De México, Mexico
| | - Gloria Castillo-Narváez
- Servicio de Alergia e Inmunología, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Col. Magdalena De Las Salinas, Gustavo A. Madero, C.P. 07760, Ciudad De México, Mexico
| | - Guillermo Velázquez-Sámano
- Servicio De Alergia e Inmunología Clínica, Hospital General De México, Dr. Balmis No.148 Col. Doctores, Cuauhtémoc, C.P. 06720, Ciudad De México, Mexico
| | - Andrea Aida Velasco-Medina
- Servicio De Alergia e Inmunología Clínica, Hospital General De México, Dr. Balmis No.148 Col. Doctores, Cuauhtémoc, C.P. 06720, Ciudad De México, Mexico
| | - Margaret Gissett Moya-Almonte
- Servicio De Alergia e Inmunología Clínica, Hospital General De México, Dr. Balmis No.148 Col. Doctores, Cuauhtémoc, C.P. 06720, Ciudad De México, Mexico
| | - Carla Marcela Vallejos-Pereira
- Servicio De Alergia e Inmunología Clínica, Hospital General De México, Dr. Balmis No.148 Col. Doctores, Cuauhtémoc, C.P. 06720, Ciudad De México, Mexico
| | - Marisol López-Hidalgo
- Sección de Estudios de Posgrado e Investigación, ENMH, Instituto Politécnico Nacional, Guillermo Massieu Helguera No. 239, Col. Frac. "La Escalera", Ticomán, Gustavo A. Madero, C.P. 07320, Ciudad De México, Mexico
| | - Marycarmen Godínez-Victoria
- Sección De Estudios De Posgrado e Investigación, ESM, Instituto Politécnico Nacional, Plan De San Luis y Díaz Mirón s/n, Col. Casco De Santo Tomas, Alcaldía Miguel Hidalgo, C.P. 11340, Ciudad De México, Mexico
| | - César A Reyes-López
- Sección de Estudios de Posgrado e Investigación, ENMH, Instituto Politécnico Nacional, Guillermo Massieu Helguera No. 239, Col. Frac. "La Escalera", Ticomán, Gustavo A. Madero, C.P. 07320, Ciudad De México, Mexico.
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Hernández-Santoyo A, Domínguez-Ramírez L, Reyes-López CA, González-Mondragón E, Hernández-Arana A, Rodríguez-Romero A. Effects of a buried cysteine-to-serine mutation on yeast triosephosphate isomerase structure and stability. Int J Mol Sci 2012; 13:10010-10021. [PMID: 22949845 PMCID: PMC3431843 DOI: 10.3390/ijms130810010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 07/24/2012] [Accepted: 07/26/2012] [Indexed: 12/01/2022] Open
Abstract
All the members of the triosephosphate isomerase (TIM) family possess a cystein residue (Cys126) located near the catalytically essential Glu165. The evolutionarily conserved Cys126, however, does not seem to play a significant role in the catalytic activity. On the other hand, substitution of this residue by other amino acid residues destabilizes the dimeric enzyme, especially when Cys is replaced by Ser. In trying to assess the origin of this destabilization we have determined the crystal structure of Saccharomyces cerevisiae TIM (ScTIM) at 1.86 Å resolution in the presence of PGA, which is only bound to one subunit. Comparisons of the wild type and mutant structures reveal that a change in the orientation of the Ser hydroxyl group, with respect to the Cys sulfhydryl group, leads to penetration of water molecules and apparent destabilization of residues 132–138. The latter results were confirmed by means of Molecular Dynamics, which showed that this region, in the mutated enzyme, collapses at about 70 ns.
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Affiliation(s)
- Alejandra Hernández-Santoyo
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, CU México D.F. 04510, Mexico; E-Mail:
| | - Lenin Domínguez-Ramírez
- División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana, Lerma, Lerma de Villada 07360, Mexico; E-Mail:
| | - César A. Reyes-López
- Laboratorio de Investigación Bioquímica, Postgrado Institucional en Biomedicina Molecular, ENMyH-Instituto Politécnico Nacional, CP 07320 México, DF, Mexico; E-Mail:
| | - Edith González-Mondragón
- Instituto de Agroindustrias, Universidad Tecnológica de la Mixteca, Huajuapan de León, Oaxaca 69000, Mexico; E-Mail:
| | - Andrés Hernández-Arana
- Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, Iztapalapa 09340, D.F., Mexico
- Authors to whom correspondence should be addressed; E-Mails: (A.H.-A.); (A.R.-R.); Tel.: +52-55-5622-4568 (A.R.-R.); Fax: +52-55-5616-2217 (A.R.-R.)
| | - Adela Rodríguez-Romero
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, CU México D.F. 04510, Mexico; E-Mail:
- Authors to whom correspondence should be addressed; E-Mails: (A.H.-A.); (A.R.-R.); Tel.: +52-55-5622-4568 (A.R.-R.); Fax: +52-55-5616-2217 (A.R.-R.)
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Sánchez-Miguel DS, Romero-Jiménez J, Reyes-López CA, Cabrera-Ávila AL, Carrillo-Ibarra N, Benítez-Cardoza CG. Chemical Unfolding of Enolase from Saccharomyces cerevisiae Exhibits a Three-State Model. Protein J 2009; 29:1-10. [DOI: 10.1007/s10930-009-9215-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Reyes-López CA, González-Mondragón E, Benítez-Cardoza CG, Chánez-Cárdenas ME, Cabrera N, Pérez-Montfort R, Hernández-Arana A. The conserved salt bridge linking two C-terminal β/α units in homodimeric triosephosphate isomerase determines the folding rate of the monomer. Proteins 2008; 72:972-9. [DOI: 10.1002/prot.21994] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Reyes-López CA, Pedraza-Escalona M, Mendoza G, Hernández-Santoyo A, Rodríguez-Romero A. A single amino acid substitution on the surface of a natural hevein isoform (Hev b 6.0202), confers different IgE recognition. FEBS Lett 2006; 580:2483-7. [PMID: 16638575 DOI: 10.1016/j.febslet.2006.03.085] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2006] [Revised: 03/23/2006] [Accepted: 03/28/2006] [Indexed: 11/23/2022]
Abstract
Decreased immune reactivity of isoforms of major allergens has been reported. However, such claims have always been based on experiments with recombinant proteins. This work describes the molecular and physicochemical characterization of a hevein (Hev b 6.0201) natural isoform (Hev b 6.0202), which is present in rubber latex from Hevea brasiliensis. The isoallergen has a single substitution Asn14Asp, which gives rise to local differences in the surface potential, as observed from the crystal structure presented here. Besides, ELISA inhibition using serum pools of adult and pediatric patients showed reduced IgE-binding capacity ( approximately 27%) with the isoallergen. Overall, these results are relevant to delineate crucial residues involved in this dominant discontinuous epitope.
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Affiliation(s)
- César A Reyes-López
- Instituto de Química, Universidad Nacional, Autónoma de México, Circuito Exterior, Cd. Universitaria, México, D.F. 04510, Mexico
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Reyes-López CA, Hernández-Santoyo A, Pedraza-Escalona M, Mendoza G, Hernández-Arana A, Rodríguez-Romero A. Insights into a conformational epitope of Hev b 6.02 (hevein). Biochem Biophys Res Commun 2004; 314:123-30. [PMID: 14715255 DOI: 10.1016/j.bbrc.2003.12.068] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Hevein (Hev b 6.02) is a major IgE-binding allergen in natural rubber latex and manufactured products. Both tryptophans (Trp(21) and Trp(23)) of the hevein molecule were chemically modified with BNPS-skatole (2-nitrophenylsulfenyl-3-methyl-3(')-bromoindolenine); derivatized allergen failed to significantly inhibit binding of serum IgE in ELISA assays. Similarly, skin prick tests showed that hevein-positive patients gave no response with the modified allergen. Dot blot experiments carried out with anti-hevein mono- and polyclonal antibodies confirmed the importance of Trp(21) and Trp(23) for antibody-recognition, and demonstrated the specific cross-reactivity of other molecules containing hevein-like domains. We also report the structure of Hev b 6.02 at an extended resolution (1.5A) and compare its surface properties around Trp residues with those of similar regions in other allergens. Overall our results indicate that the central part of the protein, which comprises three aromatic and other acidic and polar residues, constitutes a conformational epitope.
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Affiliation(s)
- César A Reyes-López
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Cd. Universitaria, 04510, Coyoacán México, DF, Mexico
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