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Bühler L, Maida A, Vogl ES, Georgiadi A, Takacs A, Kluth O, Schürmann A, Feuchtinger A, von Toerne C, Tsokanos FF, Klepac K, Wolff G, Sakurai M, Ekim Üstünel B, Nawroth P, Herzig S. Lipocalin 13 enhances insulin secretion but is dispensable for systemic metabolic control. Life Sci Alliance 2021; 4:4/4/e202000898. [PMID: 33536239 PMCID: PMC7898469 DOI: 10.26508/lsa.202000898] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 01/12/2021] [Accepted: 01/12/2021] [Indexed: 12/12/2022] Open
Abstract
Thorough preclinical evaluation reveals a negligible role of lipocalin 13 in systemic glucose and lipid metabolism. Members of the lipocalin protein family serve as biomarkers for kidney disease and acute phase inflammatory reactions, and are under preclinical development for the diagnosis and therapy of allergies. However, none of the lipocalin family members has made the step into clinical development, mostly due to their complex biological activity and the lack of in-depth mechanistic knowledge. Here, we show that the hepatokine lipocalin 13 (LCN13) triggers glucose-dependent insulin secretion and cell proliferation of primary mouse islets. However, inhibition of endogenous LCN13 expression in lean mice did not alter glucose and lipid homeostasis. Enhanced hepatic secretion of LCN13 in either diet-induced or genetic obesity led to no discernible impact on systemic glucose and lipid metabolism, neither in preventive nor therapeutic setting. Of note, loss or forced LCN13 hepatic secretion did not trigger any compensatory regulation of related lipocalin family members. Together, these data are in stark contrast to the suggested gluco-regulatory and therapeutic role of LCN13 in obesity, and imply complex regulatory steps in LCN13 biology at the organismic level mitigating its principal insulinotropic effects.
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Affiliation(s)
- Lea Bühler
- Institute for Diabetes and Cancer (IDC), Helmholtz Centre Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Joint Heidelberg-IDC Transnational Diabetes Program, Inner Medicine I, Heidelberg University Hospital, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Adriano Maida
- Institute for Diabetes and Cancer (IDC), Helmholtz Centre Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Joint Heidelberg-IDC Transnational Diabetes Program, Inner Medicine I, Heidelberg University Hospital, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Elena Sophie Vogl
- Institute for Diabetes and Cancer (IDC), Helmholtz Centre Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Joint Heidelberg-IDC Transnational Diabetes Program, Inner Medicine I, Heidelberg University Hospital, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Anastasia Georgiadi
- Institute for Diabetes and Cancer (IDC), Helmholtz Centre Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Joint Heidelberg-IDC Transnational Diabetes Program, Inner Medicine I, Heidelberg University Hospital, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Andrea Takacs
- Institute for Diabetes and Cancer (IDC), Helmholtz Centre Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Joint Heidelberg-IDC Transnational Diabetes Program, Inner Medicine I, Heidelberg University Hospital, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Oliver Kluth
- German Center for Diabetes Research (DZD), Neuherberg, Germany.,Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal, Germany
| | - Annette Schürmann
- German Center for Diabetes Research (DZD), Neuherberg, Germany.,Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal, Germany.,Institute of Nutritional Science, University of Potsdam, Potsdam, Germany
| | - Annette Feuchtinger
- Research Unit Analytical Pathology, Helmholtz Centre Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Christine von Toerne
- Research Unit Protein Science, Helmholtz Centre Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Foivos-Filippos Tsokanos
- Institute for Diabetes and Cancer (IDC), Helmholtz Centre Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Joint Heidelberg-IDC Transnational Diabetes Program, Inner Medicine I, Heidelberg University Hospital, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Katarina Klepac
- Institute for Diabetes and Cancer (IDC), Helmholtz Centre Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Joint Heidelberg-IDC Transnational Diabetes Program, Inner Medicine I, Heidelberg University Hospital, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Gretchen Wolff
- Institute for Diabetes and Cancer (IDC), Helmholtz Centre Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Joint Heidelberg-IDC Transnational Diabetes Program, Inner Medicine I, Heidelberg University Hospital, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Minako Sakurai
- Institute for Diabetes and Cancer (IDC), Helmholtz Centre Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Joint Heidelberg-IDC Transnational Diabetes Program, Inner Medicine I, Heidelberg University Hospital, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Bilgen Ekim Üstünel
- Institute for Diabetes and Cancer (IDC), Helmholtz Centre Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Joint Heidelberg-IDC Transnational Diabetes Program, Inner Medicine I, Heidelberg University Hospital, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Peter Nawroth
- Joint Heidelberg-IDC Transnational Diabetes Program, Inner Medicine I, Heidelberg University Hospital, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Stephan Herzig
- Institute for Diabetes and Cancer (IDC), Helmholtz Centre Munich, German Research Center for Environmental Health, Neuherberg, Germany .,Joint Heidelberg-IDC Transnational Diabetes Program, Inner Medicine I, Heidelberg University Hospital, Heidelberg, Germany.,Chair Molecular Metabolic Control, Medical Faculty, Technical University Munich, Munich, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
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2
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Stepanenko OV, Roginskii DO, Stepanenko OV, Kuznetsova IM, Uversky VN, Turoverov KK. Structure and stability of recombinant bovine odorant-binding protein: II. Unfolding of the monomeric forms. PeerJ 2016; 4:e1574. [PMID: 27114857 PMCID: PMC4841237 DOI: 10.7717/peerj.1574] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 12/16/2015] [Indexed: 01/27/2023] Open
Abstract
In a family of monomeric odorant-binding proteins (OBPs), bovine OBP (bOBP), that lacks conserved disulfide bond found in other OBPs, occupies unique niche because of its ability to form domain-swapped dimers. In this study, we analyzed conformational stabilities of the recombinant bOBP and its monomeric variants, the bOBP-Gly121+ mutant containing an additional glycine residue after the residue 121 of the bOBP, and the GCC-bOBP mutant obtained from the bOBP-Gly121+ form by introduction of the Trp64Cys/His155Cys double mutation to restore the canonical disulfide bond. We also analyzed the effect of the natural ligand binding on the conformational stabilities of these bOBP variants. Our data are consistent with the conclusion that the unfolding-refolding pathways of the recombinant bOBP and its mutant monomeric forms bOBP-Gly121+ and GCC-bOBP are similar and do not depend on the oligomeric status of the protein. This clearly shows that the information on the unfolding-refolding mechanism is encoded in the structure of the bOBP monomers. However, the process of the bOBP unfolding is significantly complicated by the formation of the domain-swapped dimer, and the rates of the unfolding-refolding reactions essentially depend on the conditions in which the protein is located.
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Affiliation(s)
- Olga V. Stepanenko
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Denis O. Roginskii
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Olesya V. Stepanenko
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Irina M. Kuznetsova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Vladimir N. Uversky
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
- Department of Molecular Medicine and USF Health Byrd Alzheimer’s Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Konstantin K. Turoverov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
- Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
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3
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Lalouette L, Pottier MA, Wycke MA, Boitard C, Bozzolan F, Maria A, Demondion E, Chertemps T, Lucas P, Renault D, Maibeche M, Siaussat D. Unexpected effects of sublethal doses of insecticide on the peripheral olfactory response and sexual behavior in a pest insect. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:3073-3085. [PMID: 26686856 DOI: 10.1007/s11356-015-5923-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 12/03/2015] [Indexed: 06/05/2023]
Abstract
Pesticides have long been used as the main solution to limit agricultural pests, but their widespread use resulted in chronic or diffuse environmental pollutions, development of insect resistances, and biodiversity reduction. The effects of low residual doses of these chemical products on organisms that affect both targeted species (crop pests) but also beneficial insects became a major concern, particularly because low doses of pesticides can induce unexpected positive--also called hermetic--effects on insects, leading to surges in pest population growth at greater rate than what would have been observed without pesticide application. The present study aimed to examine the effects of sublethal doses of deltamethrin, one of the most used synthetic pyrethroids, known to present a residual activity and persistence in the environment, on the peripheral olfactory system and sexual behavior of a major pest insect, the cotton leafworm Spodoptera littoralis. We highlighted here a hormetic effect of sublethal dose of deltamethrin on the male responses to sex pheromone, without any modification of their response to host-plant odorants. We also identified several antennal actors potentially involved in this hormetic effect and in the antennal detoxification or antennal stress response of/to deltamethrin exposure.
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Affiliation(s)
- Lisa Lalouette
- Sorbonne Université, UPMC-Paris 6, Institute of Ecology and Environnemental Sciences of Paris-Sensory Ecology Department, 7 Quai Saint Bernard, F-75005, Paris, France
| | - Marie-Anne Pottier
- Sorbonne Université, UPMC-Paris 6, Institute of Ecology and Environnemental Sciences of Paris-Sensory Ecology Department, 7 Quai Saint Bernard, F-75005, Paris, France
| | - Marie-Anne Wycke
- Sorbonne Université, UPMC-Paris 6, Institute of Ecology and Environnemental Sciences of Paris-Sensory Ecology Department, 7 Quai Saint Bernard, F-75005, Paris, France
| | - Constance Boitard
- Sorbonne Université, UPMC-Paris 6, Institute of Ecology and Environnemental Sciences of Paris-Sensory Ecology Department, 7 Quai Saint Bernard, F-75005, Paris, France
| | - Françoise Bozzolan
- Sorbonne Université, UPMC-Paris 6, Institute of Ecology and Environnemental Sciences of Paris-Sensory Ecology Department, 7 Quai Saint Bernard, F-75005, Paris, France
| | - Annick Maria
- Sorbonne Université, UPMC-Paris 6, Institute of Ecology and Environnemental Sciences of Paris-Sensory Ecology Department, 7 Quai Saint Bernard, F-75005, Paris, France
| | - Elodie Demondion
- Institute of Ecology and Environnemental Sciences of Paris-Sensory Ecology Department, INRA, Route de Saint-Cyr, F-78000, Versailles, France
| | - Thomas Chertemps
- Sorbonne Université, UPMC-Paris 6, Institute of Ecology and Environnemental Sciences of Paris-Sensory Ecology Department, 7 Quai Saint Bernard, F-75005, Paris, France
| | - Philippe Lucas
- Institute of Ecology and Environnemental Sciences of Paris-Sensory Ecology Department, INRA, Route de Saint-Cyr, F-78000, Versailles, France
| | - David Renault
- Université de Rennes 1, UMR CNRS 6553 Ecobio, 263 Avenue du Gal Leclerc, CS 74205, 35042, Rennes, France
| | - Martine Maibeche
- Sorbonne Université, UPMC-Paris 6, Institute of Ecology and Environnemental Sciences of Paris-Sensory Ecology Department, 7 Quai Saint Bernard, F-75005, Paris, France
| | - David Siaussat
- Sorbonne Université, UPMC-Paris 6, Institute of Ecology and Environnemental Sciences of Paris-Sensory Ecology Department, 7 Quai Saint Bernard, F-75005, Paris, France.
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4
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Shirak A, Reicher S, Uliel S, Mehlman T, Shainskaya A, Ron M, Seroussi E. Gender and sexual behavior modulate the composition of serum lipocalins in Nile tilapia (Oreochromis niloticus). Gene 2012; 504:22-30. [PMID: 22588028 DOI: 10.1016/j.gene.2012.04.092] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 03/19/2012] [Accepted: 04/30/2012] [Indexed: 11/27/2022]
Abstract
In tilapia species, plasma lipoproteins with high electrophoretic mobility function in intra- and intergender communication. Blood samples taken at onset and peak of daily sexual activity from dominant and subordinate Oreochromis niloticus males and females were fractionated by native gel electrophoresis and the fast-migrating proteins were subjected to mass spectrometry. Mining the sequence data of the Cichlid Genome Consortium, we identified 11 proteins from the lipocalin super-family and characterized their genes' structures. Phylogenetic and structural analyses subdivided these genes into two classes: (I) 3-coding-exon apolipoproteins and (II) more complex 6-coding-exon sulfide-bond-containing lipocalins. Five apolipoproteins and PTGDSL1, TBTBP, and MSP proteins were modulated by gender and sexual behavior. PTGDSL1 protein was only observed in the plasma serum of dominant males. However, the cysteine residue in the position that is crucial for synthetase activity in mammalian prostaglandin D synthetases was not conserved in PTGDSL1 or PTGDSL2 proteins. In line with previous reports suggesting their involvement in male functions as pheromone transporters, TBTBP and MSP proteins were not detected in females at the onset of daily activity. Their increasing amount in males was concordant with the increase in apolipoproteins AFP4L, APOA4a, APOA4b, APO14kD and APOC2, which were detected exclusively in dominant males, indicating a possible role in mobilization of the energy required to maintain their social hierarchy.
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Affiliation(s)
- Andrey Shirak
- Institute of Animal Science, Agricultural Research Organization, P.O. Box 6, Bet-Dagan 50250, Israel
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5
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Stopková R, Zdráhal Z, Ryba S, Sedo O, Sandera M, Stopka P. Novel OBP genes similar to hamster Aphrodisin in the bank vole, Myodes glareolus. BMC Genomics 2010; 11:45. [PMID: 20085627 PMCID: PMC2824723 DOI: 10.1186/1471-2164-11-45] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Accepted: 01/19/2010] [Indexed: 12/03/2022] Open
Abstract
Background Chemical communication in mammals involves globular lipocalins that protect and transport pheromones during their passage out of the body. Efficient communication via this protein - pheromone complex is essential for triggering multiple responses including aggression, mate choice, copulatory behaviour, and onset and synchronization of oestrus. The roles of lipocalins in communication were studied in many organisms and especially in mice (i.e. Mus musculus domesticus) which excrete Major Urinary Proteins (Mup) in excessive amounts in saliva and urine. Other mammals, however, often lack the genes for Mups or their expression is very low. Therefore, we aimed at characterization of candidate lipocalins in Myodes glareolus which are potentially linked to chemical communication. One of them is Aphrodisin which is a unique lipocalin that was previously described from hamster vaginal discharge and is known to carry pheromones stimulating copulatory behaviour in males. Results Here we show that Aphrodisin-like proteins exist in other species, belong to a group of Odorant Binding Proteins (Obp), and contrary to the expression of Aphrodisin only in hamster genital tract and parotid glands of females, we have detected these transcripts in both sexes of M. glareolus with the expression confirmed in various tissues including prostate, prepucial and salivary glands, liver and uterus. On the level of mRNA, we have detected three different gene variants. To assess their relevance for chemical communication we investigated the occurrence of particular proteins in saliva, urine and vaginal discharge. On the protein level we confirmed the presence of Obp2 and Obp3 in both saliva and urine. Appropriate bands in the range of 17-20 kDa from vaginal discharge were, however, beyond the MS detection limits. Conclusion Our results demonstrate that three novel Obps (Obp1, Obp2, and Obp3) are predominant lipocalins in Myodes urine and saliva. On the protein level we have detected further variants and thus we assume that similarly as Major Urinary Proteins in mice, these proteins may be important in chemical communication in this Cricetid rodent.
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Affiliation(s)
- Romana Stopková
- Department of Zoology, Faculty of Science, Charles University in Prague, Prague, CZ-128 44, Czech Republic
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6
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Marabotti A, Scirè A, Staiano M, Crescenzo R, Aurilia V, Tanfani F, D'Auria S. Wild-type and mutant bovine odorant-binding proteins to probe the role of the quaternary structure organization in the protein thermal stability. J Proteome Res 2009; 7:5221-9. [PMID: 19367721 DOI: 10.1021/pr800528b] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The exploration of events taking place at different timescales and affecting the structural and dynamics properties of proteins, such as the interactions of proteins with ligands and the subunits association/ dissociation, must necessarily be performed by using different methodologies, each of which specialized to highlight the different phenomena that occur when proteins are exposed to chemical or physical stress. In this work, we investigated the structure and dynamics of the wild-type bovine odorant-binding protein (wt-bOBP), which is a domain-swapped dimeric protein, and the triple mutant deswapped monomeric form of the protein (m-bOBP) to shed light on the role of the quaternary and tertiary structural organization in the protein thermal stability. Difference infrared spectra, 2D-IR correlation spectroscopy and molecular dynamics simulations were used to probe the effect of heating on protein structure and dynamics in microsecond and nanoseconds temporal ranges, respectively. The obtained results show that there is a heating-induced transition toward a less structured state in m-bOBP, that it is detectable around 70-80 degrees C. On the contrary, in wt-bOBP this transition is almost negligible, and changes are detectable in the protein spectra in the range of temperature between 75 and 85 degrees C. A detailed 3D inspection of the structure of the two proteins that takes into the account the spectroscopic results indicates that (a) ion pairs and hydrophobic interactions appear to be the major determinants responsible for the protein stability and (b) the protein intersubunit interactions confer an increased resistance toward the thermal stress.
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Affiliation(s)
- Anna Marabotti
- Istituto di Scienze dell'Alimentazione, CNR, Avellino, Italy
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7
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Stepanenko OV, Marabotti A, Kuznetsova IM, Turoverov KK, Fini C, Varriale A, Staiano M, Rossi M, D'Auria S. Hydrophobic interactions and ionic networks play an important role in thermal stability and denaturation mechanism of the porcine odorant-binding protein. Proteins 2008; 71:35-44. [DOI: 10.1002/prot.21658] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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8
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Barbour J, Neuhaus EM, Piechura H, Stoepel N, Mashukova A, Brunert D, Sitek B, Stühler K, Meyer HE, Hatt H, Warscheid B. New insight into stimulus-induced plasticity of the olfactory epithelium in Mus musculus by quantitative proteomics. J Proteome Res 2008; 7:1594-605. [PMID: 18336002 DOI: 10.1021/pr7005796] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The olfactory system is exposed to a plethora of chemical compounds throughout an organism's lifespan. Anticipation of stimuli and construction of appropriate neural filters present a significant challenge. This may be addressed via modulation of the protein composition of the sensory epithelium in response to environmental conditions. To reveal the mechanisms governing these changes, we employed a comprehensive quantitative proteomics strategy. Two groups of juvenile mice were treated with either pulsed or continuous application of octanal. After 20 days of treatment, we performed a behavioral study and conducted electrophysiological recordings from the olfactory epithelium (OE). Both treated groups demonstrated peripheral desensitization to octanal; however, only the 'continuous' group exhibited habituation. To obtain novel insight into the molecular mechanisms underpinning the peripheral desensitization to octanal, the OE proteomes of octanal-treated mice versus control were quantitatively analyzed using two-dimensional difference gel electrophoresis. We identified several significantly regulated proteins that were functionally classified as calcium-binding proteins, cytoskeletal proteins, and lipocalins. The calcium-binding proteins and cytoskeletal proteins were up-regulated in the 'pulsed' group, whereas in the 'continuous' group, four lipocalins were significantly down-regulated. Uniquely, the lipocalin odorant-binding protein Ia was drastically down-regulated in both groups. The identified proteins reflect changes throughout the entire OE, corresponding to changes in neuronal, non-neuronal, and pericellular processes. We report the regulation of several promising candidates for the investigation of odorant-induced changes of the OE. Among these proteins are different lipocalins, which seem to play a crucial role in the regulation of the sensitivity of the olfactory system.
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Affiliation(s)
- Jon Barbour
- Medizinisches Proteom-Center, Ruhr-University Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
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9
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Redondo C, Vouropoulou M, Evans J, Findlay JBC. Identification of the retinol-binding protein (RBP) interaction site and functional state of RBPs for the membrane receptor. FASEB J 2007; 22:1043-54. [PMID: 17991731 DOI: 10.1096/fj.07-8939com] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This laboratory has advanced a model whereby retinol is transported around the body bound to retinol-binding protein (RBP), is transferred across the membrane of cells by a specific receptor/transporter, and is picked up from the membrane by an intracellular homolog, cellular retinol-binding protein (CRBP). This process involves a number of protein-protein interactions, and we hypothesized that conformational changes were an integral part of the retinol transfer mechanism. Previously we identified the potential interaction site on RBP for its membrane receptor. Here we confirm by the analysis of chimera containing a grafted CD loop from RBP that this is indeed the receptor interaction site and go on to demonstrate that the conformational changes that occur to this region on the apo to holo transition in RBP also take place in a chimera binding a quite different ligand, thus establishing the concept. We have also gone on to support the hypothesis that CRBP may also bind to a receptor in the membrane. Previous evidence has indicated that one such receptor might be lecithin:retinol acyltransferase, an enzyme that catalyzes retinol esterification. Here we provide the first evidence that the plasma membrane receptor for RBP could be the same as that for CRBP. This observation offers support for the intracellular phase of the uptake process for retinol, providing an efficient and highly unique mechanism in eukaryotic biology.
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Affiliation(s)
- Clara Redondo
- Institute of Membrane and Systems Biology, Faculty of Biological Sciences, LIGHT Laboratories, Clarendon Way, University of Leeds, Leeds LS2 9JT, UK
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10
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Golebiowski J, Antonczak S, Fiorucci S, Cabrol-Bass D. Mechanistic events underlying odorant binding protein chemoreception. Proteins 2007; 67:448-58. [PMID: 17285634 DOI: 10.1002/prot.21307] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Odorant binding proteins (OBP's) are small hydrophilic proteins, belonging to the lipocalin family dedicated to bind and transport small hydrophobic ligands. Despite many works, the mechanism of ligand binding, together with the functional role of these proteins remains a topic of debate and little is known at the atomic level. The present work reports a computational study of odorants capture and release by an OBP, using both constrained and unconstrained simulations, giving a glimpse on the molecular mechanism of chemoreception. The residues at the origin of the regulation of the protein door opening are identified and a tyrosine amino-acid together with other nearby residues appear to play a crucial role in allowing this event to occur. The simulations reveal that this tyrosine and the protein's L5 loop are implicated in the ligand contact with the protein and act as an anchoring point for the ligand. The protein structural features required for the ligand entry are highly conserved among many transport proteins, suggesting that this mechanism could somewhat be extended to some members of the larger family of lipocalin.
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Affiliation(s)
- Jérôme Golebiowski
- Laboratoire de Chimie des Molecules Bioactives et des Aromes, Faculté des sciences de Nice-Sophia Antipolis, Centre National de la Recherche Scientifique, UMR 6001, Université de Nice-Sophia-Antipolis, France.
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11
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Golebiowski J, Antonczak S, Cabrol-Bass D. Molecular dynamics studies of odorant binding protein free of ligand and complexed to pyrazine and octenol. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.theochem.2006.01.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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12
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Ikematsu M, Takaoka D, Yasuda M. Odorant binding initially occurring at the central pocket in bovine odorant-binding protein. Biochem Biophys Res Commun 2005; 333:1227-33. [PMID: 15979570 DOI: 10.1016/j.bbrc.2005.06.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2005] [Accepted: 06/07/2005] [Indexed: 10/25/2022]
Abstract
Why bovine odorant-binding protein (OBPb), among OBP family, assumes a dimeric structure has been unclear. Here we clarified, by measuring the fluorescence of intrinsic tryptophan and tyrosine residues of intact OBPb and OBPb whose C-terminal 10 amino acids were deleted, that odorant enters the central pocket formed by the dimerization when OBPb first encounters odorant, and odorant with high affinity with OBPb subsequently enters the internal cavity (suggested binding site), releasing the pre-bound odorant. The internal cavity-bound odorant can be released by the binding of other odorants at another internal cavity or at the central pocket, depending on the binding odorants. Due to this mechanism enabled by the dimerization, OBPb is more reactive than other monomeric OBPs.
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Affiliation(s)
- Mineo Ikematsu
- Human Ecology Research Center, Sanyo Electric Co., Ltd., 1-1-1 Sakata, Oizumi, Ora, Gunma 370-0596, Japan.
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13
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Wojnar P, Lechner M, Redl B. Antisense down-regulation of lipocalin-interacting membrane receptor expression inhibits cellular internalization of lipocalin-1 in human NT2 cells. J Biol Chem 2003; 278:16209-15. [PMID: 12591932 DOI: 10.1074/jbc.m210922200] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
There is increasing experimental evidence demonstrating that many lipocalins bind to specific cell surface receptors. However, whereas the binding of lipocalins to their lipophilic ligands has now been characterized in much detail, there is a lack of knowledge about the nature of lipocalin receptors, the physiological role of receptor binding, and the molecular mechanism of ligand delivery. We previously identified a novel human membrane protein (lipocalin-1-interacting membrane receptor (LIMR)), which interacts with lipocalin-1 (Wojnar, P., Lechner, M., Merschak, P., and Redl, B. (2001) J. Biol. Chem. 276, 20206-20212). In the present study, we investigated the physiological role of LIMR and found this protein to be essential for mediating internalization of lipocalin-1 (Lcn-1) in NT2 cells, leading to its degradation. Whereas control NT2 cells rapidly internalized (125)I-Lcn-1 or fluorescein isothiocyanate-labeled Lcn-1, NT2 cells that were made LIMR deficient by cDNA antisense expression greatly accumulated Lcn-1 in the culture medium but did not internalize it. Because sequence and structure analysis indicated that proteins similar to LIMR are present in several organisms and at least two closely related orthologues are found in human and mouse, we suggest LIMR to be the prototype of a new family of endocytic receptors, which are topographically characterized by nine putative transmembrane domains and a characteristic large central cytoplasmic loop.
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Affiliation(s)
- Petra Wojnar
- Department of Molecular Biology, University of Innsbruck, Fritz Pregl Strasse 3, A-6020 Innsbruck, Austria
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Novikov SN, Troitskaya VT, Gladysheva OS, Churakov GA. Specific anosmia to isovaleric acid in laboratory C57BL/6 mice: recessive inheritance. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2002; 387:505-7. [PMID: 12577624 DOI: 10.1023/a:1021768919888] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- S N Novikov
- Pavlov Institute of Physiology, Russian Academy of Sciences, nab. Makarova 6, St. Petersburg, 199034 Russia
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Mazzini A, Maia A, Parisi M, Sorbi RT, Ramoni R, Grolli S, Favilla R. Reversible unfolding of bovine odorant binding protein induced by guanidinium hydrochloride at neutral pH. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1599:90-101. [PMID: 12479409 DOI: 10.1016/s1570-9639(02)00404-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
An analysis of the unfolding and refolding curves at equilibrium of dimeric bovine odorant binding protein (bOBP) has been performed. Unfolding induced by guanidinium chloride (GdnHCl) is completely reversible as far as structure and ligand binding capacity are concerned. The transition curves, as obtained by fluorescence and ellipticity measurements, are very similar and have the same protein concentration-independent midpoint (C1/2 approximately 2.6 M). This result implies a sequential, rather than a concerted, unfolding mechanism, with the involvement of an intermediate. However, since it has not been detected, this intermediate must be present in small amounts or have the same optical properties of either native or denatured protein. The thermodynamic best fit parameters, obtained according to a simple two-state model, are: deltaG degrees un,w = 5.0 +/- 0.6 kcal mol(-1), m = 1.9 +/- 0.2 kcal mol(-1) M(-1) and C1/2 = 2.6 +/- 0.1 M. The presence of the ligand dihydromyrcenol has a stabilising effect against unfolding by GdnHCl, with an extrapolated deltaG degrees un,w of 22.2 +/- 0.9 kcal mol(-1), a cooperative index of 3.2 +/- 0.3 and a midpoint of 4.6 +/- 0.4 M. The refolding curves, recorded after 24 h from dilution of denaturant are not yet at equilibrium: they show an apparently lower midpoint (C1/2 = 2.2 M), but tend to overlap the unfolding curve after several days. In contrast to chromatographic unfolding data, which fail to reveal the presence of folded intermediates, chromatographic refolding data as a function of time clearly show a rapid formation of folded monomers, followed by a slower step leading to folded dimers. Therefore, according to this result, we believe that the preferential unfolding/refolding mechanism is one in which dimer dissociation occurs before unfolding rather than the reverse.
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Affiliation(s)
- Alberto Mazzini
- Istituto Nazionale di Fisica della Materia, Unità di Parma, Italy.
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Wojnar P, Lechner M, Merschak P, Redl B. Molecular cloning of a novel lipocalin-1 interacting human cell membrane receptor using phage display. J Biol Chem 2001; 276:20206-12. [PMID: 11287427 DOI: 10.1074/jbc.m101762200] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Human lipocalin-1 (Lcn-1, also called tear lipocalin), a member of the lipocalin structural superfamily, is produced by a number of glands and tissues and is known to bind an unusually large array of hydrophobic ligands. Apart from its specific function in stabilizing the lipid film of human tear fluid, it is suggested to act as a physiological scavenger of potentially harmful lipophilic compounds, in general. To characterize proteins involved in the reception, detoxification, or degradation of these ligands, a cDNA phage-display library from human pituitary gland was constructed and screened for proteins interacting with Lcn-1. Using this method an Lcn-1 interacting phage was isolated that expressed a novel human protein. Molecular cloning and analysis of the entire cDNA indicated that it encodes a 55-kDa protein, lipocalin-1 interacting membrane receptor (LIMR), with nine putative transmembrane domains. The cell membrane location of this protein was confirmed by immunocytochemistry and Western blot analysis of membrane fractions of human NT2 cells. Independent biochemical investigations using a recombinant N-terminal fragment of LIMR also demonstrated a specific interaction with Lcn-1 in vitro. Based on these data, we suggest LIMR to be a receptor of Lcn-1 ligands. These findings constitute the first report of cloning of a lipocalin interacting, plasma membrane-located receptor, in general. In addition, a sequence comparison supports the biological relevance of this novel membrane protein, because genes with significant nucleotide sequence similarity are present in Takifugu rubripes, Drosophila melanogaster, Caenorhabditis elegans, Mus musculus, Bos taurus, and Sus scrofa. According to data derived from the human genome sequencing project, the LIMR-encoding gene has to be mapped on human chromosome 12, and its intron/exon organization could be established. The entire LIMR-encoding gene consists of about 13.7 kilobases in length and contains 16 introns with a length between 91 and 3438 base pairs.
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Affiliation(s)
- P Wojnar
- Department of Microbiology (Medical School), University of Innsbruck, Fritz Pregl Strasse 3, A-6020 Innsbruck, Austria
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Babalyan VV, Novikov SN. The pheromone inhibiting spermatogenesis in laboratory mice is associated with the urinary protein fraction. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2001; 378:208-9. [PMID: 12918329 DOI: 10.1023/a:1019294003485] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- V V Babalyan
- Pavlov Institute of Physiology, Russian Academy of Sciences, nab. Makarova 6, St. Petersburg, 199034 Russia
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Ramoni R, Vincent F, Grolli S, Conti V, Malosse C, Boyer FD, Nagnan-Le Meillour P, Spinelli S, Cambillau C, Tegoni M. The insect attractant 1-octen-3-ol is the natural ligand of bovine odorant-binding protein. J Biol Chem 2001; 276:7150-5. [PMID: 11114310 DOI: 10.1074/jbc.m010368200] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bovine odorant-binding protein (bOBP) is a dimeric lipocalin present in large amounts in the respiratory and olfactory nasal mucosa. The structure of bOBP refined at 2.0-A resolution revealed an elongated volume of electron density inside each buried cavity, indicating the presence of one (or several) naturally occurring copurified ligand(s) (Tegoni et al. (1996) Nat. Struct. Biol. 3, 863-867; Bianchet et al. (1996) Nat. Struct. Biol. 3, 934-939). In the present work, by combining mass spectrometry, x-ray crystallography (1.8-A resolution), and fluorescence, it has been unambiguously established that natural bOBP contains the racemic form of 1-octen-3-ol. This volatile substance is a typical component of bovine breath and in general of odorous body emanations of humans and animals. The compound 1-octen-3-ol is also an extremely potent olfactory attractant for many insect species, including some parasite vectors like Anopheles (Plasmodium) or Glossina (Trypanosoma). For the first time, a function can be assigned to an OBP, with a possible role of bOBP in the ecological relationships between bovine and insect species.
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Affiliation(s)
- R Ramoni
- Architecture et Fonction des Macromolécules Biologiques, Unité Mixte de Recherche 6098, CNRS and Universités Aix-Marseille I and II, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
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19
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Vincent F, Löbel D, Brown K, Spinelli S, Grote P, Breer H, Cambillau C, Tegoni M. Crystal structure of aphrodisin, a sex pheromone from female hamster. J Mol Biol 2001; 305:459-69. [PMID: 11152604 DOI: 10.1006/jmbi.2000.4241] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have solved the crystal structure of aphrodisin, a pheromonal protein inducing a copulatory behaviour in male hamster, using MAD methods with selenium, at 1.63 A resolution. The monomeric protein belongs to the lipocalin family, and possesses a disulfide bridge in a loop between strands 2 and 3. This disulfide bridge is characteristic of a family of lipocalins mainly identified in rodents, and is analogous to the fifth disulfide bridge of the long neurotoxins, such as alpha cobratoxin. An elongated electron density was found inside the buried cavity, which might represent a serendipitous ligand of unknown origin. The analysis of the water accessible surfaces of the side-chains bordering the cavity indicates that Phe76 may be the door for the natural ligand to access the cavity. This residue defines the entry of the cavity as belonging to the consensus for lipocalins. The face bearing Phe76 might also serve for the interaction with the receptor.
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Affiliation(s)
- F Vincent
- Architecture et Fonction des Macromolécules Biologiques, UMR 6098, CNRS et Universités d'Aix-Marseille I & II, 31 Chemin Joseph Aiguier, 13402, Marseille, CEDEX 20, France
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Tegoni M, Pelosi P, Vincent F, Spinelli S, Campanacci V, Grolli S, Ramoni R, Cambillau C. Mammalian odorant binding proteins. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1482:229-40. [PMID: 11058764 DOI: 10.1016/s0167-4838(00)00167-9] [Citation(s) in RCA: 172] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Odorant binding proteins (OBPs) pertain to one of the most abundant classes of proteins found in the olfactory apparatus. OBPs are a sub-class of lipocalins, defined by their property of reversibly binding volatile chemicals, that we call 'odorants'. Numerous sequences of OBPs are now available, derived from protein sequencing from nasal mucus material, or from DNA sequences. The structural knowledge of OBPs has been improved too in recent years, with the availability of two X-ray structures. The physiological role of OBPs remains, however, essentially hypothetical, and most probably, not linked to a function of odor transport. The present knowledge on OBP biochemistry, sequence and structure will be examined here in relation to the different functional hypotheses proposed for OBPs.
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Affiliation(s)
- M Tegoni
- Architecture et Fonction des Macromolécules Biologiques, URA 9039-CNRS, IFRI, Marseille, France
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Abstract
Lipocalins are characterized by multiple molecular recognition properties including the ability to bind to cell surface receptors. Receptors for a number of lipocalins have been identified. These include receptors for alpha-1-microglobulin, insecticyanin, glycodelin, retinol-binding protein, alpha-1-acid glycoprotein, beta-lactoglobulin and odorant-binding protein. The properties of these receptors are summarized and discussed.
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Affiliation(s)
- D R Flower
- The Edward Jenner Institute for Vaccine Research, Compton, Newbury, Berkshire RG20 7NN, UK.
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Vincent F, Spinelli S, Ramoni R, Grolli S, Pelosi P, Cambillau C, Tegoni M. Complexes of porcine odorant binding protein with odorant molecules belonging to different chemical classes. J Mol Biol 2000; 300:127-39. [PMID: 10864504 DOI: 10.1006/jmbi.2000.3820] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Porcine odorant binding protein (pOBP) is a monomer of 157 amino acid residues, purified in abundance from pig nasal mucosa. In contrast to the observation on lipocalins as retinol binding protein (RBP), major urinary protein (MUP) or bovine odorant binding protein (bOBP), no naturally occurring ligand was found in the beta-barrel cavity of pOBP. Porcine OBP was therefore chosen as a simple model for structure/function studies with odorant molecules. In competition experiments with tritiated pyrazine, the affinity of pOBP towards several odorant molecules belonging to different chemical classes has been found to be of the micromolar order, with a 1:1 stoichiometry. The X-ray structures of pOBP complexed to these molecules were determined at resolution between 2.15 and 1.4 A. As expected, the electron density of the odorant molecules was observed into the hydrophobic beta-barrel of the lipocalin. Inside this cavity, very few specific interactions were established between the odorant molecule and the amino acid side-chains, which did not undergo significant conformational change. The high B-factors observed for the odorant molecules as well as the existence of alternative conformations reveal a non-specific mode of binding of the odorant molecules in the cavity.
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Affiliation(s)
- F Vincent
- Architecture et Fonction des Macromolécules Biologiques, URA 9039, CNRS, IFR1, 31 Chemin Joseph Aiguier, Marseille, Cedex 20, 13402, France
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Katz A, Gvaryahu G, Robinzon B, Snapir N, Barnea A. The effect of pyrazine odor on body weight and the weight of various organs in chicks (Gallus gallus domesticus). Poult Sci 1999; 78:1786-9. [PMID: 10626656 DOI: 10.1093/ps/78.12.1786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Embryonic and posthatch long-term exposure to the odor of 2-methoxy-3-isobutyl-pyrazine (2M3IP) was examined for its potential physiological consequences as reflected in changes in BW and organ weights in domestic chicks (Gallus gallus domesticus). Experiments were run from Day 1 of incubation to the age of 3 wk with a total of 360 fertile chicken eggs. The experimental design consisted of four treatment groups: PP chicks were exposed to 2M3IP during both incubation and posthatch rearing; PC chicks were exposed to 2M3IP during incubation only; CP chicks were exposed to 2M3IP during rearing period only; CC control chicks were not exposed to 2M3IP. Chicks were weighed immediately after hatch and at 3 wk of age, when they were necropsied. Various organs (thyroid, adrenal, testes, comb, liver, spleen, abdominal fat, and the bursa of Fabricius) were removed and weighed. Body weights of both sexes in the PP group were reduced. This reduction was significant in males relative to both CP and CC groups and in females only relative to the CP group. Effects of 2M3IP exposure on the examined organs were as follows: in males, adrenal gland weight significantly increased in the PP group vs all other groups. No weight differences were found between the other inspected organs among the four treatments. In females, comb weight significantly decreased compared with the rest of the groups when 2M3IP exposure occurred during incubation (PC). Further investigation is needed to study the mechanisms that underlie the differential effects of pyrazine odor on male and female chicks.
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Affiliation(s)
- A Katz
- The Hebrew University of Jerusalem, Faculty of Agricultural, Food and Environmental Quality Sciences, Department of Animal Science, Rehovot, Israel
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Miller RE, Fayen JD, Chakraborty S, Weber MC, Tykocinski ML. A receptor for the lipocalin placental protein 14 on human monocytes. FEBS Lett 1998; 436:455-60. [PMID: 9801168 DOI: 10.1016/s0014-5793(98)01184-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Human placental protein 14 (PP14), a member of the lipocalin structural superfamily, is an abundant amniotic fluid glycoprotein with documented immunoinhibitory activities. While receptors have been characterized for several other lipocalins, none have been reported to date for PP14. In the present study, two-color immunofluorescence and flow cytometry was used to screen peripheral blood mononuclear cell subpopulations for their capacity to engage fluoresceinated recombinant PP14. The tagged PP14 bound strongly in a specific and saturable fashion to CD14+ (monocyte lineage) cells, but not to CD20+ (B cell lineage) or CD3+ (T cell lineage) cells. This binding was both pH- and temperature-sensitive, and was reduced by proteolytic pre-digestion of the cells with trypsin or proteinase K. Scatchard analysis demonstrated a single class of receptors on CD14+ cells, with a K(D) of approximately 1 x 10(-8) and approximately 10-35,000 receptors per cell. These findings constitute the first report of a cell surface-associated binding protein for PP14 and set the stage for exploring the molecular mechanisms of PP14-mediated signaling and immunomodulation.
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Affiliation(s)
- R E Miller
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH 44106, USA
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Affiliation(s)
- N Jones
- Department of Otorhinolaryngology-Head and Neck Surgery, Queen's Medical Centre, Nottingham, U.K
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Bianchet MA, Bains G, Pelosi P, Pevsner J, Snyder SH, Monaco HL, Amzel LM. The three-dimensional structure of bovine odorant binding protein and its mechanism of odor recognition. NATURE STRUCTURAL BIOLOGY 1996; 3:934-9. [PMID: 8901871 DOI: 10.1038/nsb1196-934] [Citation(s) in RCA: 158] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Odorant binding protein (OBP) is the major odorant binding component of mammalian nasal mucosa. The two structures of bovine OBP reported in this paper (one crystallized as purified and one soaked in the presence of a selenium-containing odorant) show that: (i) the OBP dimer is composed of two compact domains related by an approximate two-fold axis of symmetry; (ii) between residues 122 and 123 the polypeptide chains cross from one domain to the other such that each domain is formed by residues from both monomers; (iii) purified OBP already contains two bound odorant molecules (one per monomer)-odorant binding occurs by replacement of these molecules with the added odorant; and (iv) the structure of the odorant binding site can explain OBP's extraordinarily broad odorant specificity.
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Affiliation(s)
- M A Bianchet
- Department of Biophysics and Biophysical Chemistry, University of Pisa, Italy.
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