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Gupta AK, Kasturiratna D, Nguyen T, Pardo L. A New Family of BAN Estimators for Polytomous Logistic Regression Models based on ϕ- Divergence Measures. STAT METHOD APPL-GER 2006. [DOI: 10.1007/s10260-006-0008-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Cortés-Selva F, Jiménez IA, Munoz-Martínez F, Campillo M, Bazzocchi IL, Pardo L, Ravelo AG, Castanys S, Gamarro F. Dihydro-beta-agarofuran sesquiterpenes: a new class of reversal agents of the multidrug resistance phenotype mediated by P-glycoprotein in the protozoan parasite Leishmania. Curr Pharm Des 2005; 11:3125-39. [PMID: 16178749 DOI: 10.2174/1381612054864920] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Leishmaniasis is the most important emerging and uncontrolled infectious disease and the second cause of death among parasitic diseases, after Malaria. One of the main problems concerning the control of infectious diseases is the increased resistance to usual drugs. Overexpression of P-glycoprotein (Pgp)-like transporters represents a very efficient mechanism to reduce the intracellular accumulation of drugs in cancer cells and parasitic protozoans, thus conferring a multidrug resistance (MDR) phenotype. Pgps are active pumps belonging to the ATP-binding cassette (ABC) superfamily of proteins. The inhibition of the activity of these proteins represents an interesting way to control drug resistance both in cancer and in infectious diseases. Most conventional mammalian Pgp-MDR modulators are ineffective in the modulation of Pgp activity in the protozoan parasite Leishmania. Consequently, there is a necessity to find effective modulators of Pgp-MDR for protozoan parasites. In this review we describe a rational strategy developed to find specific Pgp-MDR modulators in Leishmania, using natural and semisynthetic dihydro-beta-agarofuran sesquiterpenes from Celastraceae plants. A series of these compounds have been tested on a MDR Leishmania tropica line overexpressing a Pgp transporter to determine their ability to revert the resistance phenotype and to modulate intracellular drug accumulation. Almost all of these natural compounds showed potent reversal activity with different degrees of selectivity and a significant low toxicity. The three-dimensional quantitative structure-activity relationship using the comparative molecular similarity indices analysis (CoMSIA), was employed to characterize the requirements of these sesquiterpenes as modulators at Pgp-like transporter in Leishmania.
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Menéndez ML, Pardo JA, Pardo L, Zografos K. On tests of symmetry, marginal homogeneity and quasi-symmetry in two-way contingency tables based on minimum φ-divergence estimator with constraints. J STAT COMPUT SIM 2005. [DOI: 10.1080/00949650412331299094] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Landaburu E, Morales D, Pardo L. Divergence-based estimation and testing with misclassified data. Stat Pap (Berl) 2005. [DOI: 10.1007/bf02762841] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Menéndez ML, Pardo JA, Pardo L, Zografos K. A preliminary test in classification and probabilities of misclassification. STATISTICS-ABINGDON 2005. [DOI: 10.1080/02331880500097986] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Coyle PK, Christie S, Fodor P, Fuchs K, Giesser B, Gutierrez A, Lynn J, Weinstock-Guttman B, Pardo L. Multiple sclerosis gender issues: clinical practices of women neurologists. Mult Scler 2005; 10:582-8. [PMID: 15471377 DOI: 10.1191/1352458504ms1083oa] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Substantially more women than men develop multiple sclerosis (MS), but information about the effects of MS and gender-specific issues such as pregnancy, breastfeeding, menstruation and hormone use is lacking. A survey study of neurologists' practice patterns was undertaken to elicit information about gender-specific topics and the use of disease-modifying MS therapies (DMT) including the interferons and glatiramer acetate (GA). A total of 147 surveys were returned. Half of respondents require patients to discontinue DMT during pregnancy, while 35% encourage discontinuation. Among those who allow patients to continue therapy, half consider GA to be safer during pregnancy than the interferons. Nearly 86% of respondents do not use DMT in patients who are breastfeeding. Among the 11% who actually prescribe during breastfeeding, most recommend GA. Neurologists generally leave the decision to breastfeed up to patients, and most refer patients to obstetrician/gynaecologists for counselling about contraception or hormone replacement therapy. The survey results described here provide insight into how neurologists manage reproductive health issues among women with MS.
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Menéndez ML, Pardo JA, Pardo L. Tests of Symmetry in Three-dimensional Contingency Tables Based on Phi-divergence Statistics. J Appl Stat 2004. [DOI: 10.1080/0266476042000280373] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Lopez-Rodriguez M, Benhamu B, Morcillo M, Porras E, Lavandera J, Pardo L. Serotonin 5-HT7 Receptor Antagonists. ACTA ACUST UNITED AC 2004. [DOI: 10.2174/1568015043356931] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Morales D, Pardo L, Pardo MC, Vajda I. Rényi statistics for testing composite hypotheses in general exponential models. STATISTICS-ABINGDON 2004. [DOI: 10.1080/02331880310001634647] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Menéndez M, Pardo J, Pardo L, Zografos K. On tests of homogeneity based on minimum φ-divergence estimator with constraints. Comput Stat Data Anal 2003. [DOI: 10.1016/s0167-9473(02)00207-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Morales D, Pardo L, Vajda I. Asymptotic laws for disparity statistics in product multinomial models. J MULTIVARIATE ANAL 2003. [DOI: 10.1016/s0047-259x(02)00042-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Menendez M, Pardo J, Pardo L. Tests for Bivariate Symmetry Against Ordered Alternatives in Square Contingency Tables. AUST NZ J STAT 2003. [DOI: 10.1111/1467-842x.00265] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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65
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Calzada ML, González A, Poyato R, Pardo L. Photo-sensitive sol–gel solutions for the low-temperature UV-assisted processing of PbTiO3based ferroelectric thin films. ACTA ACUST UNITED AC 2003. [DOI: 10.1039/b300036m] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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66
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Pardo J, Pardo L, Zografos K. Minimum φ-divergence estimators with constraints in multinomial populations. J Stat Plan Inference 2002. [DOI: 10.1016/s0378-3758(01)00113-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Menéndez ML, Pardo JA, Pardo L. RAO'S STATISTIC FOR THE ANALYSIS OF UNIFORM ASSOCIATION IN CROSS-CLASSIFICATIONS. COMMUN STAT-THEOR M 2001. [DOI: 10.1081/sta-100108452] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Menéndez ML, Morales D, Pardo L, Vajda I. Asymptotic distributions of φ‐divergences of hypothetical and observed frequencies on refined partitions. STAT NEERL 2001. [DOI: 10.1111/1467-9574.00069] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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69
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López-Rodríguez ML, Murcia M, Benhamú B, Viso A, Campillo M, Pardo L. 3-D-QSAR/CoMFA and recognition models of benzimidazole derivatives at the 5-HT(4) receptor. Bioorg Med Chem Lett 2001; 11:2807-11. [PMID: 11597405 DOI: 10.1016/s0960-894x(01)00517-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
3-D-QSAR/CoMFA methodology and computational simulation of ligand recognition have been successfully applied to explain the binding affinities of a series of benzimidazole derivatives 1-24 acting at serotonin 5-HT(4)Rs. Both derived computational models have facilitated the identification of the structural elements of the ligands that are key to high 5-HT(4)R affinity. The results provide the tools for predicting the affinity of related compounds, and for guiding the design and synthesis of new ligands with predetermined affinities and selectivity.
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López-Rodríguez ML, Murcia M, Benhamú B, Olivella M, Campillo M, Pardo L. Computational model of the complex between GR113808 and the 5-HT4 receptor guided by site-directed mutagenesis and the crystal structure of rhodopsin. J Comput Aided Mol Des 2001; 15:1025-33. [PMID: 11989623 DOI: 10.1023/a:1014895611874] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A computational model of the transmembrane domain of the human 5-HT4 receptorcomplexed with the GR113808 antagonist was constructed from the crystal structure of rhodopsin and the putative residues of the ligand-binding site, experimentally determined by site-directed mutagenesis. The recognition mode of GR113808 consist of: (i) the ionic interaction between the protonated amine and Asp3.32; (ii) the hydrogen bond between the carbonylic oxygen and Ser5.43; (iii) the hydrogen bond between the ether oxygen and Asn6.55; (iv) the hydrogen bond between the C-H groups adjacent to the protonated piperidine nitrogen and the pi electrons of Phe6.51; and (v) the pi-sigma aromatic-aromatic interaction between the indole ring and Phe6.52. This computational model offers structural indications about the role of Asp3.32, Ser5.43, Phe6.51, Phe6.52, and Asn6.55 in the experimental binding affinities. Asp3.32Asn mutation does not affect the binding of GR113808 because the loss of binding affinity from an ion pair to a charged hydrogen bond is compensated by the larger energetical penalty of Asp to disrupt its side chain environment in the ligand-free form, and the larger interaction between Phe6.51 and the piperidine ring of the ligand in the mutant receptor. In the Phe6.52Val mutant the indole ring of the ligand replaces the interaction with Phe6.52 by a similarly intense interaction with Tyr5.38, with no significant effect in the binding of GR113808. The mutation of Asn6.55 to Leu replaces the hydrogen bond of the ether oxygen of the ligand from Asn6.55 to Cys5.42, with a decrease of binding affinity that approximately equals the free energy difference between the SH...O and NH...O hydrogen bonds. Because these residues are also present in the other members of the neurotransmitter family of G protein-coupled receptors, these findings will also serve for our understanding of the binding of related ligands to their cognate receptors.
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Trelles MA, Pardo L, Trelles O, Velez M, García-Solana L, Rigau J, Chamorro TJ. Clinical and histologic effects of facial skin rejuvenation with pulsed- and continuous-wave flash-scanned CO(2) lasers. Aesthet Surg J 2001; 21:399-411. [PMID: 19331921 DOI: 10.1067/maj.2001.119150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
LEARNING OBJECTIVES The reader is presumed to have some understanding of the use of lasers in skin resurfacing. After studying the article, the participant should be able to: Physicians may earn 1 hour of Category 1 CME credit by successfully completing the examination based on material covered in this article. The examination begins on page 409. BACKGROUND The selection of the ideal laser for facial resurfacing is debatable. OBJECTIVE The purpose of the study was to determine whether any clinical and histologic differences existed in short- and long-term results after treatment with the Coherent UltraPulse 5000G laser (a pulsed laser; PL) and the Sharplan Silk Touch laser (a continuous-wave laser [CWL] with a flash scanner). METHODS Eight patients underwent facial resurfacing treatment on different areas. In each case, one side was treated with the PL and the other with the CWL. The condition of the patients and the treated tissue were monitored periodically after treatment. Histologic assessment of punch biopsies was performed 3 months and 1 year after treatment with hematoxylin-eosin, Masson trichromic, and Verhoeff's stains. RESULTS The areas treated with the PL achieved earlier epithelialization with a good appearance. Longer-lasting erythema was observed on the side treated with the CWL. On a histologic level, although the PL-treated tissue epithelialized more quickly, at 3 months and 1 year the collagen was better compacted and better aligned in the CWL-treated tissue, and the macroscopic appearance of the CWL-treated areas was more enhanced. CONCLUSIONS The more active vascularization seen in the CWL-treated tissue, associated with the longer-lasting erythema and possibly greater collateral thermal injury, is possibly the reason for the better collagenization and remodeling of collagen and elastin fibers as compared with the results with the PL-treated tissue. This may explain the longer effect associated with CWL treatment. The clinician would do well to bear in mind the histologic findings as well as the macroscopic clinical results when assessing the long-term effects of laser skin resurfacing. (Aesthetic Surg J 2001;21:399-411.).
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Trelles MA, Pardo L, Ayliffe P, Trelles K, Vélez M, García-Solana L. Patients' answers to a postoperative questionnaire related to laser resurfacing. Facial Plast Surg 2001; 17:187-92. [PMID: 11673808 DOI: 10.1055/s-2001-17969] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022] Open
Abstract
To date there is no information that evaluates, from the patient's point of view, the experience of undergoing CO(2) laser skin resurfacing. This article investigates the outcome of laser resurfacing for various cutaneous problems with respect to the patient's expectations and experiences and the surgeon's opinions. Patients were entered into the study prospectively and presented with a questionnaire, at 12 months after treatment, to evaluate the patient's skin resurfacing experience. All patients received standardized preoperative counseling and underwent a standardized surgical protocol, conducted by the same surgeon. Eighty-eight percent of patients considered the result of the laser resurfacing to be very good, and 97% indicated that they had experienced little pain or discomfort. Nevertheless, 77% of patients stated that they would be unwilling to undergo another resurfacing procedure. This discrepancy is most likely the result of the patients' experiences in relation to the degree of erythema afterward. Most patients stated a desire to have more information regarding the procedure, particularly with respect to their experiences concerning postoperative erythema and exudates in the treated area. From the study it can be concluded that patients require extensive preoperative counseling, including a full explanation of all possible sequelae of these procedures to improve the patient's experience.
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Menéndez ML, Pardo JA, Pardo L. Csiszar’s ϕ-divergences for testing the order in a Markov chain. Stat Pap (Berl) 2001. [DOI: 10.1007/s003620100061] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Govaerts C, Lefort A, Costagliola S, Wodak SJ, Ballesteros JA, Van Sande J, Pardo L, Vassart G. A conserved Asn in transmembrane helix 7 is an on/off switch in the activation of the thyrotropin receptor. J Biol Chem 2001; 276:22991-9. [PMID: 11312274 DOI: 10.1074/jbc.m102244200] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The thyrotropin (TSH) receptor is an interesting model to study G protein-coupled receptor activation as many point mutations can significantly increase its basal activity. Here, we identified a molecular interaction between Asp(633) in transmembrane helix 6 (TM6) and Asn(674) in TM7 of the TSHr that is crucial to maintain the inactive state through conformational constraint of the Asn. We show that these residues are perfectly conserved in the glycohormone receptor family, except in one case, where they are exchanged, suggesting a direct interaction. Molecular modeling of the TSHr, based on the high resolution structure of rhodopsin, strongly favors this hypothesis. Our approach combining site-directed mutagenesis with molecular modeling shows that mutations disrupting this interaction, like the D633A mutation in TM6, lead to high constitutive activation. The strongly activating N674D (TM7) mutation, which in our modeling breaks the TM6-TM7 link, is reverted to wild type-like behavior by an additional D633N mutation (TM6), which would restore this link. Moreover, we show that the Asn of TM7 (conserved in most G protein-coupled receptors) is mandatory for ligand-induced cAMP accumulation, suggesting an active role of this residue in activation. In the TSHr, the conformation of this Asn residue of TM7 would be constrained, in the inactive state, by its Asp partner in TM6.
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Govaerts C, Blanpain C, Deupi X, Ballet S, Ballesteros JA, Wodak SJ, Vassart G, Pardo L, Parmentier M. The TXP motif in the second transmembrane helix of CCR5. A structural determinant of chemokine-induced activation. J Biol Chem 2001; 276:13217-25. [PMID: 11278962 DOI: 10.1074/jbc.m011670200] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CCR5 is a G-protein-coupled receptor activated by the chemokines RANTES (regulated on activation normal T cell expressed and secreted), macrophage inflammatory protein 1alpha and 1beta, and monocyte chemotactic protein 2 and is the main co-receptor for the macrophage-tropic human immunodeficiency virus strains. We have identified a sequence motif (TXP) in the second transmembrane helix of chemokine receptors and investigated its role by theoretical and experimental approaches. Molecular dynamics simulations of model alpha-helices in a nonpolar environment were used to show that a TXP motif strongly bends these helices, due to the coordinated action of the proline, which kinks the helix, and of the threonine, which further accentuates this structural deformation. Site-directed mutagenesis of the corresponding Pro and Thr residues in CCR5 allowed us to probe the consequences of these structural findings in the context of the whole receptor. The P84A mutation leads to a decreased binding affinity for chemokines and nearly abolishes the functional response of the receptor. In contrast, mutation of Thr-82(2.56) into Val, Ala, Cys, or Ser does not affect chemokine binding. However, the functional response was found to depend strongly on the nature of the substituted side chain. The rank order of impairment of receptor activation is P84A > T82V > T82A > T82C > T82S. This ranking of impairment parallels the bending of the alpha-helix observed in the molecular simulation study.
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MESH Headings
- Amino Acid Sequence
- Amino Acid Substitution
- Animals
- Binding Sites
- CHO Cells
- Cattle
- Chemokine CCL4
- Chemokine CCL5/pharmacokinetics
- Chemokine CCL5/pharmacology
- Chemokine CCL8
- Chemokines/pharmacology
- Cricetinae
- GTP-Binding Proteins/metabolism
- Humans
- Macrophage Inflammatory Proteins/pharmacology
- Mice
- Models, Molecular
- Molecular Sequence Data
- Monocyte Chemoattractant Proteins/pharmacology
- Mutagenesis, Site-Directed
- Protein Structure, Secondary
- Receptors, CCR5/chemistry
- Receptors, CCR5/drug effects
- Receptors, CCR5/physiology
- Receptors, Chemokine/chemistry
- Receptors, HIV/chemistry
- Receptors, HIV/drug effects
- Receptors, HIV/physiology
- Recombinant Proteins/chemistry
- Recombinant Proteins/drug effects
- Recombinant Proteins/metabolism
- Rhodopsin/chemistry
- Sequence Alignment
- Sequence Homology, Amino Acid
- Transfection
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