1
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Liu S, Gao F, Wang R, Li W, Wang S, Zhang X. Molecular Characteristics of the Fatty-Acid-Binding Protein (FABP) Family in Spirometra mansoni-A Neglected Medical Tapeworm. Animals (Basel) 2023; 13:2855. [PMID: 37760255 PMCID: PMC10525997 DOI: 10.3390/ani13182855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/05/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
The plerocercoid larva of the tapeworm Spirometra mansoni can parasitize humans and animals, causing serious parasitic zoonosis. The molecular characteristics and adaptive parasitism mechanism of Spirometra tapeworms are still unknown. In this study, 11 new members of the fatty-acid-binding protein (FABP) family were characterized in S. mansoni. A clustering analysis showed 11 SmFABPs arranged into two groups, and motif patterns within each group had similar organizations. RT-qPCR showed that SmFABPs were highly expressed in the adult stage, especially in gravid proglottid. A high genetic diversity of SmFABPs and relative conservation of FABPs in medical platyhelminthes were observed in the phylogenetic analysis. Immunolocalization revealed that natural SmFABP is mainly located in the tegument and parenchymal tissue of the plerocercoid and the uterus, genital pores, and cortex of adult worms. rSmFABP can build a more stable holo form when binding with palmitic acid to protect the hydrolytic sites of the protein. A fatty acid starvation induction test suggested that SmFABP might be involved in fatty acid absorption, transport, and metabolism in S. mansoni. The findings in this study will lay the foundation to better explore the underlying mechanisms of FABPs involved in Spirometra tapeworms as well as related taxa.
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Affiliation(s)
| | | | | | | | | | - Xi Zhang
- Department of Parasitology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China; (S.L.); (F.G.); (R.W.); (W.L.); (S.W.)
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2
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Bélgamo JA, Alberca LN, Pórfido JL, Romero FNC, Rodriguez S, Talevi A, Córsico B, Franchini GR. Application of target repositioning and in silico screening to exploit fatty acid binding proteins (FABPs) from Echinococcus multilocularis as possible drug targets. J Comput Aided Mol Des 2020; 34:1275-1288. [PMID: 33067653 DOI: 10.1007/s10822-020-00352-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 10/09/2020] [Indexed: 10/23/2022]
Abstract
Fatty acid binding proteins (FABPs) are small intracellular proteins that reversibly bind fatty acids and other hydrophobic ligands. In cestodes, due to their inability to synthesise fatty acids and cholesterol de novo, FABPs, together with other lipid binding proteins, have been proposed as essential, involved in the trafficking and delivery of such lipophilic metabolites. Pharmacological agents that modify specific parasite FABP function may provide control of lipid signalling pathways, inflammatory responses and metabolic regulation that could be of crucial importance for the parasite development and survival. Echinococcus multilocularis and Echinococcus granulosus are, respectively, the causative agents of alveolar and cystic echinococcosis (or hydatidosis). These diseases are included in the World Health Organization's list of priority neglected tropical diseases. Here, we explore the potential of FABPs from cestodes as drug targets. To this end, we have applied a target repurposing approach to identify novel inhibitors of Echinococcus spp. FABPs. An ensemble of computational models was developed and applied in a virtual screening campaign of DrugBank library. 21 hits belonging to the applicability domain of the ensemble models were identified, and 3 of the hits were assayed against purified E. multilocularis FABP, experimentally confirming the model's predictions. Noteworthy, this is to our best knowledge the first report on isolation and purification of such four FABP, for which initial structural and functional characterization is reported here.
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Affiliation(s)
- Julián A Bélgamo
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Facultad de Ciencias Médicas, Universidad Nacional de La Plata (UNLP)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), La Plata, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Lucas N Alberca
- Laboratory of Bioactive Research and Development (LIDeB), Faculty of Exact Sciences, Universidad Nacional de La Plata (UNLP), Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Jorge L Pórfido
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Facultad de Ciencias Médicas, Universidad Nacional de La Plata (UNLP)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), La Plata, Argentina.,Institut Pasteur Montevideo, Montevideo, Uruguay
| | - Franco N Caram Romero
- Laboratory of Bioactive Research and Development (LIDeB), Faculty of Exact Sciences, Universidad Nacional de La Plata (UNLP), Buenos Aires, Argentina
| | - Santiago Rodriguez
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Facultad de Ciencias Médicas, Universidad Nacional de La Plata (UNLP)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), La Plata, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Alan Talevi
- Laboratory of Bioactive Research and Development (LIDeB), Faculty of Exact Sciences, Universidad Nacional de La Plata (UNLP), Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Betina Córsico
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Facultad de Ciencias Médicas, Universidad Nacional de La Plata (UNLP)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), La Plata, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Gisela R Franchini
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Facultad de Ciencias Médicas, Universidad Nacional de La Plata (UNLP)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), La Plata, Argentina. .,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
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3
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Liu R, Zhang Y, Gao J, Li X. Effects of octylphenol exposure on the lipid metabolism and microbiome of the intestinal tract of Rana chensinensis tadpole by RNAseq and 16s amplicon sequencing. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 197:110650. [PMID: 32315788 DOI: 10.1016/j.ecoenv.2020.110650] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 03/20/2020] [Accepted: 04/14/2020] [Indexed: 06/11/2023]
Abstract
Octylphenol (OP) is a widely distributed endocrine disrupting chemical (EDC), and can be commonly found in various and diverse environmental media. Previous studies have reported that OP exposure could cause many adverse effects on aquatic animals. However, knowledge concerning the impact of OP on lipid metabolism in amphibians was still limited. In our study, Rana chensinensis tadpoles were exposed to different OP concentrations (0, 10-8, 10-7 and 10-6 mol/L) from the Gosner stage (Gs) 25-38. The RNA-seq analysis of tadpole intestines was explored by RNA-seq, and six differentially expressed genes (DEGs) related to the fat digestion and absorption were validated by RT-qPCR. Moreover, we used 16s amplicon sequencing to evaluate effects of OP on intestinal microbiome in tadpoles, further determining the variations of lipid metabolism. Our results revealed that OP exposure influenced gene expression levels related to fat digestion and absorption and led to alteration of structure and composition of intestinal microbiome. At the phylum level, the Firmicutes/Bacteroidetes ratio was gradually decreased in OP exposure groups, which disrupted lipid metabolism. According to the results of intestinal microbial functional prediction, OP exposure interfered with metabolic function and increased risk of disease. These data provide us with powerful resources to assess the effects of OP on lipid metabolism by integrating RNAseq and 16s amplicon sequencing analysis of intestinal tract and intestinal microbiome.
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Affiliation(s)
- Rong Liu
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, China
| | - Yuhui Zhang
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, China
| | - Jinshu Gao
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, China
| | - Xinyi Li
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, China.
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4
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Barletta GP, Franchini G, Corsico B, Fernandez-Alberti S. Fatty Acid and Retinol-Binding Protein: Unusual Protein Conformational and Cavity Changes Dictated by Ligand Fluctuations. J Chem Inf Model 2019; 59:3545-3555. [PMID: 31365253 DOI: 10.1021/acs.jcim.9b00364] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Lipid-binding proteins (LBPs) are soluble proteins responsible for the uptake, transport, and storage of a large variety of hydrophobic lipophilic molecules including fatty acids, steroids, and other lipids in the cellular environment. Among the LBPs, fatty acid binding proteins (FABPs) present preferential binding affinities for long-chain fatty acids. While most of FABPs in vertebrates and invertebrates present similar β-barrel structures with ligands accommodated in their central cavity, parasitic nematode worms exhibit additional unusual α-helix rich fatty acid- and retinol-binding proteins (FAR). Herein, we report the comparison of extended molecular dynamics (MD) simulations performed on the ligand-free and palmitic acid-bond states of the Necator americanus FAR-1 (Na-FAR-1) with respect to other classical β-barrel FABPs. Principal component analysis (PCA) has been used to identify the different conformations adopted by each system during MD simulations. The α-helix fold encompasses a complex internal ligand-binding cavity with a remarkable conformational plasticity that allows reversible switching between distinct states in the holo-Na-FAR-1. The cavity can change up to one-third of its size affected by conformational changes of the protein-ligand complex. Besides, the ligand inside the cavity is not fixed but experiences large conformational changes between bent and stretched conformations. These changes in the ligand conformation follow changes in the cavity size dictated by the transient protein conformation. On the contrary, protein-ligand complex in β-barrel FABPs fluctuates around a unique conformation. The significantly more flexible holo-Na-FAR-1 ligand-cavity explains its larger ligand multiplicity respect to β-barrel FABPs.
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Affiliation(s)
- G P Barletta
- Universidad Nacional de Quilmes/CONICET , Roque Saenz Peña 352 , B1876BXD Bernal , Argentina
| | - G Franchini
- Instituto de Investigaciones Bioquímicas de La Plata , CONICET-UNLP, Facultad de Ciencias Médicas , calles 60 y 120 s/n , 1900 La Plata , Argentina
| | - B Corsico
- Instituto de Investigaciones Bioquímicas de La Plata , CONICET-UNLP, Facultad de Ciencias Médicas , calles 60 y 120 s/n , 1900 La Plata , Argentina
| | - S Fernandez-Alberti
- Universidad Nacional de Quilmes/CONICET , Roque Saenz Peña 352 , B1876BXD Bernal , Argentina
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5
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Characterization and functional analysis of fatty acid binding protein from the carcinogenic liver fluke, Opisthorchis viverrini. Parasitol Int 2017; 66:419-425. [DOI: 10.1016/j.parint.2016.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 03/27/2016] [Accepted: 04/29/2016] [Indexed: 01/29/2023]
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6
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Structural coalescence underlies the aggregation propensity of a β-barrel protein motif. PLoS One 2017; 12:e0170607. [PMID: 28187186 PMCID: PMC5302452 DOI: 10.1371/journal.pone.0170607] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 01/07/2017] [Indexed: 02/07/2023] Open
Abstract
A clear understanding of the structural foundations underlying protein aggregation is an elusive goal of central biomedical importance. A step toward this aim is exemplified by the β-barrel motif represented by the intestinal fatty acid binding protein (IFABP) and two abridged all-β sheet forms (Δ98Δ and Δ78Δ). At odds with the established notion that a perturbation of the native fold should necessarily favor a buildup of intermediate forms with an enhanced tendency to aggregate, the intrinsic stability (ΔG°H2O) of these proteins does not bear a straightforward correlation with their trifluoroethanol (TFE)-induced aggregation propensity. In view of this fact, we found it more insightful to delve into the connection between structure and stability under sub-aggregating conditions (10% TFE). In the absence of the co-solvent, the abridged variants display a common native-like region decorated with a disordered C-terminal stretch. Upon TFE addition, an increase in secondary structure content is observed, assimilating them to the parent protein. In this sense, TFE perturbs a common native like region while exerting a global compaction effect. Importantly, in all cases, fatty acid binding function is preserved. Interestingly, energetic as well as structural diversity in aqueous solution evolves into a common conformational ensemble more akin in stability. These facts reconcile apparent paradoxical findings related to stability and rates of aggregation. This scenario likely mimics the accrual of aggregation-prone species in the population, an early critical event for the development of fibrillation.
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7
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Cecconi F, Shahzad MA, Marini Bettolo Marconi U, Vulpiani A. Frequency-control of protein translocation across an oscillating nanopore. Phys Chem Chem Phys 2017; 19:11260-11272. [DOI: 10.1039/c6cp08156h] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The translocation of a lipid binding protein (LBP) is studied using a phenomenological coarse-grained computational model that simplifies both chain and pore geometry.
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Affiliation(s)
| | | | | | - Angelo Vulpiani
- Dipartimento di Fisica
- Università “Sapienza” di Roma
- Italy
- Centro Linceo Interdisciplinare “B. Segre”
- Accademia dei Lincei
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8
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Curto LM, Angelani CR, Delfino JM. Intervening in the β-barrel structure of lipid binding proteins: consequences on folding, ligand-binding and aggregation propensity. Prostaglandins Leukot Essent Fatty Acids 2015; 93:37-43. [PMID: 25242388 DOI: 10.1016/j.plefa.2014.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 07/26/2014] [Accepted: 08/01/2014] [Indexed: 02/02/2023]
Abstract
Natural β-folds manage to fold up successfully. By contrast, attempts to dissect fragments or peptides from well folded β-sheet proteins have met with insurmountable difficulties. Here we briefly review selected successful cases of intervention on the well-known scaffold of intestinal fatty acid binding protein (IFABP). Lessons from these examples might set guidelines along the design of proteins belonging to this class. Impact of modifications on topology, binding and aggregation is highlighted. With the aid of abridged variants of IFABP we focus on key structural features responsible for the assembly into oligomeric forms or aggregates.
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Affiliation(s)
- L M Curto
- Department of Biological Chemistry and Institute of Biochemistry and Biophysics (IQUIFIB), School of Pharmacy and Biochemistry, University of Buenos Aires, Junín 956, C1113AAD Buenos Aires, Argentina
| | - C R Angelani
- Department of Biological Chemistry and Institute of Biochemistry and Biophysics (IQUIFIB), School of Pharmacy and Biochemistry, University of Buenos Aires, Junín 956, C1113AAD Buenos Aires, Argentina
| | - J M Delfino
- Department of Biological Chemistry and Institute of Biochemistry and Biophysics (IQUIFIB), School of Pharmacy and Biochemistry, University of Buenos Aires, Junín 956, C1113AAD Buenos Aires, Argentina.
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9
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Wilson C, Ramai D, Serjanov D, Lama N, Levinger L, Chang EJ. Tethered domains and flexible regions in tRNase Z(L), the long form of tRNase Z. PLoS One 2013; 8:e66942. [PMID: 23874404 PMCID: PMC3714273 DOI: 10.1371/journal.pone.0066942] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 05/13/2013] [Indexed: 11/30/2022] Open
Abstract
tRNase Z, a member of the metallo-β-lactamase family, endonucleolytically removes the pre-tRNA 3′ trailer in a step central to tRNA maturation. The short form (tRNase ZS) is the only one found in bacteria and archaebacteria and is also present in some eukaryotes. The homologous long form (tRNase ZL), exclusively found in eukaryotes, consists of related amino- and carboxy-domains, suggesting that tRNase ZL arose from a tandem duplication of tRNase ZS followed by interdependent divergence of the domains. X-ray crystallographic structures of tRNase ZS reveal a flexible arm (FA) extruded from the body of tRNase Z remote from the active site that binds tRNA far from the scissile bond. No tRNase ZL structures have been solved; alternative biophysical studies are therefore needed to illuminate its functional characteristics. Structural analyses of tRNase ZL performed by limited proteolysis, two dimensional gel electrophoresis and mass spectrometry establish stability of the amino and carboxy domains and flexibility of the FA and inter-domain tether, with implications for tRNase ZL function.
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Affiliation(s)
- Christopher Wilson
- Department of Biology, York College of The City University of New York, Jamaica, New York, United States of America
| | - Daryl Ramai
- Department of Chemistry, York College of The City University of New York, Jamaica, New York, United States of America
| | - Dmitri Serjanov
- Department of Biology, York College of The City University of New York, Jamaica, New York, United States of America
| | - Neema Lama
- Department of Chemistry, York College of The City University of New York, Jamaica, New York, United States of America
| | - Louis Levinger
- Department of Biology, York College of The City University of New York, Jamaica, New York, United States of America
| | - Emmanuel J. Chang
- Department of Chemistry, York College of The City University of New York, Jamaica, New York, United States of America
- * E-mail:
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10
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Curto LM, Angelani CR, Caramelo JJ, Delfino JM. Truncation of a β-barrel scaffold dissociates intrinsic stability from its propensity to aggregation. Biophys J 2013. [PMID: 23199921 DOI: 10.1016/j.bpj.2012.09.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Δ98Δ is a functional all-β sheet variant of intestinal fatty acid binding protein (IFABP) that was generated by controlled proteolysis. This framework is useful to study the molecular determinants related to aggregation of β-barrel proteins. Albeit displaying increased conformational plasticity, Δ98Δ exhibits a nativelike β-barrel topology and is able to support a cooperative folding behavior. Here we present a comparative study of IFABP and Δ98Δ regarding their conformational perturbation and aggregation propensity triggered by trifluoroethanol. Both proteins share a common nucleation-elongation mechanism, whereby the rate-limiting step is the formation of stable dimeric nuclei followed by the association of monomers to the growing aggregates. Despite leading to a less stable structure, the extensive truncation of IFABP yields a form exhibiting a somewhat lower tendency to aggregate. This finding appears at odds with the established notion that a perturbation of the native compact fold should necessarily favor the population of aggregation-prone species. In addition to the aggregation propensity dictated by a given amino-acid sequence, our contention holds that long-range interactions might also play a major role in determining the overall aggregation propensity.
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Affiliation(s)
- Lucrecia M Curto
- Department of Biological Chemistry and Institute of Biochemistry and Biophysics, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
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11
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Porfido JL, Alvite G, Silva V, Kennedy MW, Esteves A, Corsico B. Direct interaction between EgFABP1, a fatty acid binding protein from Echinococcus granulosus, and phospholipid membranes. PLoS Negl Trop Dis 2012; 6:e1893. [PMID: 23166848 PMCID: PMC3499409 DOI: 10.1371/journal.pntd.0001893] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 09/21/2012] [Indexed: 12/28/2022] Open
Abstract
Background Growth and maintenance of hydatid cysts produced by Echinococcus granulosus have a high requirement for host lipids for biosynthetic processes, membrane building and possibly cellular and developmental signalling. This requires a high degree of lipid trafficking facilitated by lipid transporter proteins. Members of the fatty acid binding protein (FABP) family have been identified in Echinococcus granulosus, one of which, EgFABP1 is expressed at the tegumental level in the protoscoleces, but it has also been described in both hydatid cyst fluid and secretions of protoscoleces. In spite of a considerable amount of structural and biophysical information on the FABPs in general, their specific functions remain mysterious. Methodology/Principal Findings We have investigated the way in which EgFABP1 may interact with membranes using a variety of fluorescence-based techniques and artificial small unilamellar vesicles. We first found that bacterial recombinant EgFABP1 is loaded with fatty acids from the synthesising bacteria, and that fatty acid binding increases its resistance to proteinases, possibly due to subtle conformational changes induced on EgFABP1. By manipulating the composition of lipid vesicles and the ionic environment, we found that EgFABP1 interacts with membranes in a direct contact, collisional, manner to exchange ligand, involving both ionic and hydrophobic interactions. Moreover, we observed that the protein can compete with cytochrome c for association with the surface of small unilamellar vesicles (SUVs). Conclusions/Significance This work constitutes a first approach to the understanding of protein-membrane interactions of EgFABP1. The results suggest that this protein may be actively involved in the exchange and transport of fatty acids between different membranes and cellular compartments within the parasite. Echinococcus granulosus is the causative agent of hydatidosis, a zoonotic infection that affects humans and livestock, representing a public health and economic burden in many countries. Since the parasites are unable to synthesise most of their lipids de novo, they must acquire them from the host and then deliver them by carrier proteins to specific destinations. E. granulosus produces in abundance proteins of the fatty acid binding protein (FABP) family, one of which, EgFABP1 has been characterised at the structural and ligand binding levels, but it has not been studied in terms of the mechanism of its interaction with membranes. We have investigated the lipid transport properties and protein-membrane interaction characteristics of EgFABP1 by applying biophysical techniques. We found that EgFABP1 interacts with membranes by a mechanism which involves direct contact with them to exchange their cargo. Given that the protein has been found in the secretions of the parasite, the implications of its direct interactions with host membranes should be considered.
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Affiliation(s)
- Jorge L. Porfido
- Instituto de Investigaciones Bioquímicas de La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Gabriela Alvite
- Sección Bioquímica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Valeria Silva
- Instituto de Investigaciones Bioquímicas de La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Malcolm W. Kennedy
- Institute of Molecular, Cell and Systems Biology, and Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Adriana Esteves
- Sección Bioquímica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Betina Corsico
- Instituto de Investigaciones Bioquímicas de La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
- * E-mail:
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12
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Franchini GR, Curto LM, Caramelo JJ, Delfino JM. Dissection of a beta-barrel motif leads to a functional dimer: the case of the intestinal fatty acid binding protein. Protein Sci 2010; 18:2592-602. [PMID: 19844951 DOI: 10.1002/pro.273] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A lingering issue in the area of protein engineering is the optimal design of beta motifs. In this regard, the framework provided by intestinal fatty acid binding protein (IFABP) was successfully chosen to explore the consequences on structure and function of the redesign of natural motifs. A truncated form of IFABP (Delta 98 Delta) served to illustrate the nonintuitive notion that the integrity of the beta-barrel can indeed be compromised with no effect on the ability to attain a native-like fold. This is most likely the outcome of the key role played by the preservation of essential core residues. In the search for the minimal structural determinants of this fold, Delta 98 Delta offered room for further intervention. A dissection of this protein leads to a new abridged variant, Delta 78 Delta, containing 60% of the amino acids of IFABP. Spectroscopic analyses indicate that Delta 78 Delta retains substantial beta-sheet content and preserves tertiary interactions, displaying cooperative unfolding and binding activity. Most strikingly, this construct adopts a remarkably stable dimeric structure in solution. This phenomenon takes advantage of the inherent structural plasticity of this motif, likely profitting from edge-to-edge interactions between beta-sheets, whereas avoiding the most commonly occurring outcome represented by aggregation.
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Affiliation(s)
- Gisela R Franchini
- Department of Biological Chemistry and Institute of Biochemistry and Biophysics (IQUIFIB), School of Pharmacy and Biochemistry, University of Buenos Aires, C1113AAD, Buenos Aires, Argentina
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13
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Curto LM, Caramelo JJ, Franchini GR, Delfino JM. Delta98Delta, a minimalist model of antiparallel beta-sheet proteins based on intestinal fatty acid binding protein. Protein Sci 2009; 18:735-46. [PMID: 19309727 DOI: 10.1002/pro.71] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The design of beta-barrels has always been a formidable challenge for de novo protein design. For instance, a persistent problem is posed by the intrinsic tendency to associate given by free edges. From the opposite standpoint provided by the redesign of natural motifs, we believe that the intestinal fatty acid binding protein (IFABP) framework allows room for intervention, giving rise to abridged forms from which lessons on beta-barrel architecture and stability could be learned. In this context, Delta98Delta (encompassing residues 29-126 of IFABP) emerges as a monomeric variant that folds properly, retaining functional activity, despite lacking extensive stretches involved in the closure of the beta-barrel. Spectroscopic probes (fluorescence and circular dichroism) support the existence of a form preserving the essential determinants of the parent structure, albeit endowed with enhanced flexibility. Chemical and physical perturbants reveal cooperative unfolding transitions, with evidence of significant population of intermediate species in equilibrium, structurally akin to those transiently observed in IFABP. The recognition by the natural ligand oleic acid exerts a mild stabilizing effect, being of a greater magnitude than that found for IFABP. In summary, Delta98Delta adopts a monomeric state with a compact core and a loose periphery, thus pointing to the nonintuitive notion that the integrity of the beta-barrel can indeed be compromised with no consequence on the ability to attain a native-like and functional fold.
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Affiliation(s)
- Lucrecia María Curto
- Department of Biological Chemistry and Institute of Biochemistry and Biophysics (IQUIFIB), School of Pharmacy and Biochemistry, University of Buenos Aires, C1113AAD Buenos Aires, Argentina
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14
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Velkov T, Chuang S, Wielens J, Sakellaris H, Charman WN, Porter CJH, Scanlon MJ. The Interaction of Lipophilic Drugs with Intestinal Fatty Acid-binding Protein. J Biol Chem 2005; 280:17769-76. [PMID: 15722357 DOI: 10.1074/jbc.m410193200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Intestinal fatty acid-binding protein (I-FABP) is a small protein that binds long-chain dietary fatty acids in the cytosol of the columnar absorptive epithelial cells (enterocytes) of the intestine. The binding cavity of I-FABP is much larger than is necessary to bind a fatty acid molecule, which suggests that the protein may be able to bind other hydrophobic and amphipathic ligands such as lipophilic drugs. Herein we describe the binding of three structurally diverse lipophilic drugs, bezafibrate, ibuprofen (both R- and S-isomers) and nitrazepam to I-FABP. The rank order of affinity for I-FABP determined for these compounds was found to be R-ibuprofen approximately bezafibrate > S-ibuprofen >> nitrazepam. The binding affinities were not directly related to aqueous solubility or partition coefficient of the compounds; however, the freely water-soluble drug diltiazem showed no affinity for I-FABP. Drug-I-FABP interaction interfaces were defined by analysis of chemical shift perturbations in NMR spectra, which revealed that the drugs bound within the central fatty acid binding cavity. Each drug participated in a different set of interactions within the cavity; however, a number of common contacts were observed with residues also involved in fatty acid binding. These data suggest that the binding of non-fatty acid lipophilic drugs to I-FABP may increase the cytosolic solubility of these compounds and thereby facilitate drug transport from the intestinal lumen across the enterocyte to sites of distribution and metabolism.
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Affiliation(s)
- Tony Velkov
- Department of Medicinal Chemistry, Pharmaceutics, and Microbiology, Monash University, Parkville 3052, Victoria, Australia
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