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Dijkstra JM, Kondo Y. Comprehensive Sequence Analysis of Parvalbumins in Fish and Their Comparison with Parvalbumins in Tetrapod Species. BIOLOGY 2022; 11:biology11121713. [PMID: 36552222 PMCID: PMC9774829 DOI: 10.3390/biology11121713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/18/2022] [Accepted: 11/19/2022] [Indexed: 11/29/2022]
Abstract
Parvalbumins are small molecules with important functions in Ca2+ signaling, but their sequence comparisons to date, especially in fish, have been relatively poor. We here, characterize sequence motifs that distinguish parvalbumin subfamilies across vertebrate species, as well as those that distinguish individual parvalbumins (orthologues) in fish, and map them to known parvalbumin structures. As already observed by others, all classes of jawed vertebrates possess parvalbumins of both the α-parvalbumin and oncomodulin subfamilies. However, we could not find convincing phylogenetic support for the common habit of classifying all non-α-parvalbumins together as "β-parvalbumins." In teleost (modern bony) fish, we here distinguish parvalbumins 1-to-10, of which the gene copy number can differ between species. The genes for α-parvalbumins (pvalb6 and pvalb7) and oncomodulins (pvalb8 and pvalb9) are well conserved between teleost species, but considerable variation is observed in their copy numbers of the non-α/non-oncomodulin genes pvalb1-to-5 and pvalb10. Teleost parvalbumins 1-to-4 are hardly distinguishable from each other and are highly expressed in muscle, and described allergens belong to this subfamily. However, in some fish species α-parvalbumin expression is also high in muscle. Pvalb5 and pvalb10 molecules form distinct lineages, the latter even predating the origin of teleosts, but have been lost in some teleost species. The present study aspires to be a frame of reference for future studies trying to compare different parvalbumins.
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Affiliation(s)
- Johannes M. Dijkstra
- Center for Medical Science, Fujita Health University, Dengaku-gakubo 1-98, Toyoake 470-1192, Japan
| | - Yasuto Kondo
- Department of Pediatrics, Fujita Health University Bantane Hospital, Otobashi 3-6-10, Nakagawa, Nagoya 454-8509, Japan
- Correspondence:
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2
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What Is Parvalbumin for? Biomolecules 2022; 12:biom12050656. [PMID: 35625584 PMCID: PMC9138604 DOI: 10.3390/biom12050656] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 04/25/2022] [Accepted: 04/28/2022] [Indexed: 12/28/2022] Open
Abstract
Parvalbumin (PA) is a small, acidic, mostly cytosolic Ca2+-binding protein of the EF-hand superfamily. Structural and physical properties of PA are well studied but recently two highly conserved structural motifs consisting of three amino acids each (clusters I and II), which contribute to the hydrophobic core of the EF-hand domains, have been revealed. Despite several decades of studies, physiological functions of PA are still poorly known. Since no target proteins have been revealed for PA so far, it is believed that PA acts as a slow calcium buffer. Numerous experiments on various muscle systems have shown that PA accelerates the relaxation of fast skeletal muscles. It has been found that oxidation of PA by reactive oxygen species (ROS) is conformation-dependent and one more physiological function of PA in fast muscles could be a protection of these cells from ROS. PA is thought to regulate calcium-dependent metabolic and electric processes within the population of gamma-aminobutyric acid (GABA) neurons. Genetic elimination of PA results in changes in GABAergic synaptic transmission. Mammalian oncomodulin (OM), the β isoform of PA, is expressed mostly in cochlear outer hair cells and in vestibular hair cells. OM knockout mice lose their hearing after 3–4 months. It was suggested that, in sensory cells, OM maintains auditory function, most likely affecting outer hair cells’ motility mechanisms.
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3
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The Highly Conservative Cysteine of Oncomodulin as a Feasible Redox Sensor. Biomolecules 2021; 11:biom11010066. [PMID: 33419032 PMCID: PMC7825312 DOI: 10.3390/biom11010066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/01/2021] [Accepted: 01/03/2021] [Indexed: 11/17/2022] Open
Abstract
Oncomodulin (Ocm), or parvalbumin β, is an 11-12 kDa Ca2+-binding protein found inside and outside of vertebrate cells, which regulates numerous processes via poorly understood mechanisms. Ocm consists of two active Ca2+-specific domains of the EF-hand type ("helix-loop-helix" motif), covered by an EF-hand domain with inactive EF-hand loop, which contains a highly conservative cysteine with unknown function. In this study, we have explored peculiarities of the microenvironment of the conservative Cys18 of recombinant rat Ocm (rWT Ocm), redox properties of this residue, and structural/functional sensitivity of rWT Ocm to the homologous C18S substitution. We have found that pKa
of the Cys18 thiol lays beyond the physiological pH range. The measurement of redox dependence of rWT Ocm thiol-disulfide equilibrium (glutathione redox pair) showed that redox potential of Cys18 for the metal-free and Ca2+-loaded protein is of -168 mV and -176 mV, respectively. Therefore, the conservative thiol of rWT Ocm is prone to disulfide dimerization under physiological redox conditions. The C18S substitution drastically reduces α-helices content of the metal-free and Mg2+-bound Ocm, increases solvent accessibility of its hydrophobic residues, eliminates the cooperative thermal transition in the apo-protein, suppresses Ca2+/Mg2+ affinity of the EF site, and accelerates Ca2+ dissociation from Ocm. The distinct structural and functional consequences of the minor structural modification of Cys18 indicate its possible redox sensory function. Since some other EF-hand proteins also contain a conservative redox-sensitive cysteine located in an inactive EF-hand loop, it is reasonable to suggest that in the course of evolution, some of the EF-hands attained redox sensitivity at the expense of the loss of their Ca2+ affinity.
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4
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Climer LK, Cox AM, Reynolds TJ, Simmons DD. Oncomodulin: The Enigmatic Parvalbumin Protein. Front Mol Neurosci 2019; 12:235. [PMID: 31649505 PMCID: PMC6794386 DOI: 10.3389/fnmol.2019.00235] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Accepted: 09/13/2019] [Indexed: 01/21/2023] Open
Abstract
EF-hand Ca2+-binding protein family members, α- and β-parvalbumins have been studied for decades. Yet, considerable information is lacking distinguishing functional differences between mammalian α-parvalbumin (PVALB) and oncomodulin (OCM), a branded β-parvalbumin. Herein, we provide an overview detailing the current body of work centered around OCM as an EF-Hand Ca2+-binding protein and describe potential mechanisms of OCM function within the inner ear and immune cells. Additionally, we posit that OCM is evolutionarily distinct from PVALB and most other β-parvalbumins. This review summarizes recent studies pertaining to the function of OCM and emphasizes OCM as a parvalbumin possessing a unique cell and tissue distribution, Ca2+ buffering capacity and phylogenetic origin.
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Affiliation(s)
- Leslie K Climer
- Department of Biology, Baylor University, Waco, TX, United States.,Department of Psychology and Neuroscience, Baylor University, Waco, TX, United States
| | - Andrew M Cox
- Department of Biology, Baylor University, Waco, TX, United States.,Department of Psychology and Neuroscience, Baylor University, Waco, TX, United States
| | | | - Dwayne D Simmons
- Department of Biology, Baylor University, Waco, TX, United States.,Department of Psychology and Neuroscience, Baylor University, Waco, TX, United States.,Biomedical Sciences Program, Baylor University, Waco, TX, United States
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5
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Permyakov SE, Vologzhannikova AA, Khorn PA, Shevelyova MP, Kazakov AS, Emelyanenko VI, Denesyuk AI, Denessiouk K, Uversky VN, Permyakov EA. Comprehensive analysis of the roles of 'black' and 'gray' clusters in structure and function of rat β-parvalbumin. Cell Calcium 2018; 75:64-78. [PMID: 30176502 DOI: 10.1016/j.ceca.2018.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 08/26/2018] [Indexed: 01/05/2023]
Abstract
Recently we found two highly conserved structural motifs in the proteins of the EF-hand calcium binding protein family. These motifs provide a supporting scaffold for the Ca2+ binding loops and contribute to the hydrophobic core of the EF-hand domain. Each structural motif forms a cluster of three amino acids called cluster I ('black' cluster) and cluster II ('grey' cluster). Cluster I is much more conserved and mostly incorporates aromatic amino acids. In contrast, cluster II includes a mix of aromatic, hydrophobic, and polar amino acids. The 'black' and 'gray' clusters in rat β-parvalbumin consist of F48, A100, F103 and G61, L64, M87, respectively. In the present work, we sequentially substituted these amino acids residues by Ala, except Ala100, which was substituted by Val. Physical properties of the mutants were studied by circular dichroism, scanning calorimetry, dynamic light scattering, chemical crosslinking, and fluorescent probe methods. The Ca2+ and Mg2+ binding affinities of these mutants were evaluated by intrinsic fluorescence and equilibrium dialysis methods. In spite of a rather complicated pattern of contributions of separate amino acid residues of the 'black' and 'gray' clusters into maintenance of rat β-parvalbumin structural and functional status, the alanine substitutions in the cluster I cause noticeably more pronounced changes in various structural parameters of proteins, such as hydrodynamic radius of apo-form, thermal stability of Ca2+/Mg2+-loaded forms, and total energy of Ca2+ binding in comparison with the changes caused by amino acid substitutions in the cluster II. These findings were further supported by the outputs of computational analysis of the effects of these mutations on the intrinsic disorder predisposition of rat β-parvalbumin, which also indicated that local intrinsic disorder propensities and the overall levels of predicted disorder were strongly affected by mutations in the cluster I, whereas mutations in cluster II had less pronounced effects. These results demonstrate that amino acids of the cluster I provide more essential contribution to the maintenance of structuraland functional properties of the protein in comparison with the residues of the cluster II.
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Affiliation(s)
- Sergei E Permyakov
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia; Department of Biomedical Engineering, Pushchino State Institute of Natural Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Alisa A Vologzhannikova
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Polina A Khorn
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Marina P Shevelyova
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Alexei S Kazakov
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Victor I Emelyanenko
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Alexander I Denesyuk
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia; Structural Bioinformatics Laboratory, Faculty of Science and Engineering, Åbo Akademi University, Turku, 20520, Finland
| | - Konstantin Denessiouk
- Structural Bioinformatics Laboratory, Faculty of Science and Engineering, Åbo Akademi University, Turku, 20520, Finland; Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Pharmacy, Åbo Akademi University, Turku, 20520, Finland
| | - Vladimir N Uversky
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia; Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA.
| | - Eugene A Permyakov
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia; Department of Biomedical Engineering, Pushchino State Institute of Natural Sciences, Pushchino, Moscow Region, 142290, Russia
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6
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Hauk TG, Müller A, Lee J, Schwendener R, Fischer D. Neuroprotective and axon growth promoting effects of intraocular inflammation do not depend on oncomodulin or the presence of large numbers of activated macrophages. Exp Neurol 2008; 209:469-82. [DOI: 10.1016/j.expneurol.2007.09.020] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2007] [Revised: 09/03/2007] [Accepted: 09/11/2007] [Indexed: 10/22/2022]
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7
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Abstract
Relative to other parvalbumin isoforms, the mammalian beta-parvalbumin (oncomodulin) displays attenuated divalent ion affinity. High-resolution structural data for the Ca(2+)-bound protein have provided little insight into the physical basis for this behavior, prompting an examination of the unliganded state. This article describes the solution structure and peptide backbone dynamics of Ca(2+)-free rat beta-parvalbumin (beta-PV). Ca(2+) removal evidently provokes significant structural alterations. Interaction between the D helix and the AB domain in the Ca(2+)-bound protein is greatly diminished in the apo-form, permitting the D helix to straighten. There is also a significant reorganization of the hydrophobic core and a concomitant remodeling of the interface between the AB and CD-EF domains. These modifications perturb the orientation of the C and D helices, and the energetic penalty associated with their reversal could contribute to the low-affinity signature of the CD site. By contrast, Ca(2+) removal causes a comparatively minor perturbation of the E and F helices, consistent with the more typical divalent ion affinity observed for the EF site. Ca(2+)-free rat beta-PV retains structural rigidity on the picosecond-nanosecond timescale. At 20 degrees C, the majority of amide vectors show no evidence for motion on timescales above 20 ps, and the average order parameter for the entire molecule is 0.92.
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Affiliation(s)
- Michael T Henzl
- Department of Biochemistry, University of Missouri-Columbia, Columbia, Missouri 65211, USA.
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8
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Bouhallab S, Henry G, Caussin F, Croguennec T, Fauquant J, Mollé D. Copper-catalyzed formation of disulfide-linked dimer of bovineβ-lactoglobulin. ACTA ACUST UNITED AC 2004. [DOI: 10.1051/lait:2004023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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9
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King NM, Elkins KM, Nelson DJ. Reactivity of the invariant cysteine of silver hake parvalbumin (Isoform B) with dithionitrobenzoate (DTNB) and the effect of differing buffer species on reactivity. J Inorg Biochem 1999. [DOI: 10.1016/s0162-0134(99)00113-0] [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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10
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Cox JA, Durussel I, Scott DJ, Berchtold MW. Remodeling of the AB site of rat parvalbumin and oncomodulin into a canonical EF-hand. EUROPEAN JOURNAL OF BIOCHEMISTRY 1999; 264:790-9. [PMID: 10491125 DOI: 10.1046/j.1432-1327.1999.00650.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Parvalbumin (PV) and the homologous protein oncomodulin (OM) contain three EF-hand motifs, but the first site (AB) cannot bind Ca2+. Here we aimed to recreate the putative ancestral proteins [D19-28E]PV and [D19-28E]OM by replacing the 10-residue-long nonfunctional loop in the AB site by a 12-residue canonical loop. To create an optical conformational probe we also expressed the homologs with a F102W replacement. Unexpectedly, in none of the proteins did the mutation reactivate the AB site. The AB-remodeled parvalbumins bind two Ca2+ ions with strong positive cooperativity (nH = 2) and moderate affinity ([Ca2+]0.5 = 2 microM), compared with [Ca2+]0.5 = 37 nM and nH = 1 for the wild-type protein. Increasing Mg2+ concentrations changed nH from 2 to 0.65, but without modification of the [Ca2+]0. 5-value. CD revealed that the Ca2+ and Mg2+ forms of the remodeled parvalbumins lost one-third of their alpha helix content compared with the Ca2+ form of wild-type parvalbumin. However, the microenvironment of single Trp residues in the hydrophobic cores, monitored using intrinsic fluorescence and difference optical density, is the same. The metal-free remodeled parvalbumins possess unfolded conformations. The AB-remodeled oncomodulins also bind two Ca2+ with [Ca2+]0.5 = 43 microM and nH = 1.45. Mg2+ does not affect Ca2+ binding. Again the Ca2+ forms display two-thirds of the alpha-helical content in the wild-type, while their core is still strongly hydrophobic as monitored by Trp and Tyr fluorescence. The metal-free oncomodulins are partially unfolded and seem not to possess a hydrophobic core. Our data indicate that AB-remodeled parvalbumin has the potential to regulate cell functions, whereas it is unlikely that [D19-28E]OM can play a regulatory role in vivo. The predicted evolution of the AB site from a canonical to an abortive EF-hand may have been dictated by the need for stronger interaction with Mg2+ and Ca2+, and a high conformational stability of the metal-free forms.
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Affiliation(s)
- J A Cox
- Department of Biochemistry, University of Geneva, Switzerland.
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11
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Sakaguchi N, Henzl MT, Thalmann I, Thalmann R, Schulte BA. Oncomodulin is expressed exclusively by outer hair cells in the organ of Corti. J Histochem Cytochem 1998; 46:29-40. [PMID: 9405492 DOI: 10.1177/002215549804600105] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Oncomodulin (OM) is a small, acidic calcium-binding protein first discovered in a rat hepatoma and later found in placental cytotrophoblasts, the pre-implantation embryo, and in a wide variety of neoplastic tissues. OM was considered to be exclusively an oncofetal protein until its recent detection in extracts of the adult guinea pig's organ of Corti. Here we report that light and electron microscopic immunostaining of gerbil, rat, and mouse inner ears with a monoclonal antibody against recombinant rat OM localizes the protein exclusively in cochlear outer hair cells (OHCs). At the ultrastructural level, high gold labeling density was seen overlying the nucleus, cytoplasm, and the cuticular plate of gerbil OHCs. Few, if any, gold particles were present over intracellular organelles and the stereocilia. Staining of a wide range of similarly processed gerbil organs failed to detect immunoreactive OM in any other adult tissues. The mammalian genome encodes one alpha- and one beta-isoform of parvalbumin (PV). The widely distributed alpha PV exhibits a very high affinity for Ca2+ and is believed to serve as a Ca2+ buffer. By contrast, OM, the mammalian beta PV, displays a highly attenuated affinity for Ca2+, consistent with a Ca2+-dependent regulatory function. The exclusive association of OM with cochlear OHCs in mature tissues is likely to have functional relevance. Teleological considerations favor its involvement in regulating some aspect of OHC electromotility. Although the fast electromotile response of OHCs does not require Ca2+, its gain and magnitude are modulated by efferent innervation. Therefore, OM may be involved in mediation of intracellular responses to cholinergic stimulation, which are known to be Ca2+ regulated. (J Histochem Cytochem 46:29-39, 1998)
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MESH Headings
- Animals
- Antibodies, Monoclonal/metabolism
- Calcium-Binding Proteins/biosynthesis
- Calcium-Binding Proteins/immunology
- Female
- Gerbillinae
- Hair Cells, Auditory, Outer/cytology
- Hair Cells, Auditory, Outer/metabolism
- Hair Cells, Auditory, Outer/ultrastructure
- Immunohistochemistry
- Male
- Mice
- Mice, Inbred C57BL
- Microscopy, Immunoelectron
- Organ Specificity
- Organ of Corti/cytology
- Organ of Corti/metabolism
- Paraffin Embedding
- Parvalbumins/biosynthesis
- Protein Isoforms/biosynthesis
- Rats
- Rats, Sprague-Dawley
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Affiliation(s)
- N Sakaguchi
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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12
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Durussel I, Pauls TL, Cox JA, Berchtold MW. Chimeras of parvalbumin and oncomodulin involving exchange of the complete CD site show that the Ca2+/Mg2+ specificity is an intrinsic property of the site. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 242:256-63. [PMID: 8973641 DOI: 10.1111/j.1432-1033.1996.0256r.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Rat parvalbumin (PV) and oncomodulin (OM) differ in the affinity and selectivity of metal binding to their CD site, which is a high-affinity Ca2+/Mg(2+)-mixed site in PV and a low-affinity Ca(2+)-specific site in OM. To assess to what degree the Ca2+/Mg2+ specificity and affinity of an EF-hand motif in a protein is intrinsically determined by its sequence, the complete CD sites were exchanged, yielding two chimeras, [S41-Q71]PV and [D41-S71]OM. The optical characteristics of a Trp102, inserted in the hydrophobic core of PV, OM and the two chimeras, are very similar in all four proteins, which suggests that the hydrophobic core is qualitatively similar in the chimeras as in the parent proteins. Direct Ca2+ and Mg2+ binding monitored by flow dialysis and gel filtration revealed that [S41-Q71]PV binds only one Mg2+ with an intrinsic affinity K'Mg2+ of 3.0 x 10(4) M-1 and two Ca2+ with an identical K'Ca2+ of 4.4 x 10(6) M-1, whereas [D41-S71]OM binds two Mg2+ with a mean K'Mg2+ of 2 x 10(4) M-1 and two Ca2+ with a K'Ca2+ of 1.3 x 10(7) M-1. K'Ca2+ of the CD site of [S41-Q71]PV was 2.5-fold higher than of the CD site in [W102]OM, but 5-6-fold lower than that of the CD site in [W102]PV. In [D41-S71]OM, K'Ca2+ of the CD site was twofold lower than in [W102]PV, but eightfold higher than in [W102]OM. These results indicate that the sequence of the CD site determines its Ca2+/Mg(2+)-specificity, whereas its affinity for Ca2+ influenced by the protein into which the CD site is inserted. The inserted CD site in turn influences the affinity of the EF site to which it is paired in the host protein and the paired sites display an equalized affinity for Ca2+. Mg2+ decreases the affinity of the chimeras for Ca2+, but not according to a simple competition model. The Mg2+ antagonism is much more pronounced in [D41-S71]OM than in [S41-Q71]PV, but in each chimera the CD and EF site are quantitatively affected in the same manner. Thus, [S41-Q71]PV which can only bind a single Mg2+ ion, displays a Ca2+/Mg(2+)-antagonism for both sites with a KMg.compet of 2.3 x 10(2) M-1. These results confirm the 'equalizer' principle in the cation-binding parameters of [S41-Q71]PV: both sites display the same Ca2+ affinity and Mg2+ antagonism. In [D41-S71]OM with its two Ca2+/Mg2+ sites the antagonism shows qualitatively the same complexity as in wild-type PV, although it is somewhat weaker in amplitude.
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Affiliation(s)
- I Durussel
- Department of Biochemistry, University of Geneva, Switzerland
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13
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Hapak RC, Zhao H, Henzl MT. Oligomerization of an avian thymic parvalbumin. Chemical evidence for a Ca(2+)-specific conformation. FEBS Lett 1994; 349:295-300. [PMID: 8050585 DOI: 10.1016/0014-5793(94)00691-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
CPV3, the third parvalbumin isoform to be identified in the chicken, is produced exclusively in the thymus gland. Although parvalbumins are typically cysteine-deficient, CPV3 contains two cysteine residues, at positions 18 and 72. The reported three-dimensional parvalbumin structures suggest that the side chain of cysteine-72 should be solvent-accessible. Accordingly, we find that CPV3 readily forms disulfide-linked oligomers in the absence of reducing agents. The reaction, employing either O2 or ferricyanide ion as the oxidant, is apparently restricted to the Ca(2+)-bound form of the protein. The differing reactivity of the Ca2+, Mg2+, and apo-forms has significant structural implications.
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Affiliation(s)
- R C Hapak
- Biochemistry Department, University of Missouri, Columbia 65211
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14
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Reactivity of Protein sulfhydryl groups with disulfides. Tetrahedron Lett 1994. [DOI: 10.1016/s0040-4039(00)76765-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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16
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Föhr UG, Weber BR, Müntener M, Staudenmann W, Hughes GJ, Frutiger S, Banville D, Schäfer BW, Heizmann CW. Human alpha and beta parvalbumins. Structure and tissue-specific expression. EUROPEAN JOURNAL OF BIOCHEMISTRY 1993; 215:719-27. [PMID: 8354278 DOI: 10.1111/j.1432-1033.1993.tb18084.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
alpha and beta parvalbumins are Ca(2+)-binding proteins of the EF-hand type. We determined the protein sequence of human brain alpha parvalbumin by mass spectrometry and cloned human beta parvalbumin (or oncomodulin) from genomic DNA and preterm placental cDNA. beta parvalbumin differs in 54 positions from alpha parvalbumin and lacks the C-terminal amino acid 109. From MS analyses of alpha and beta parvalbumins we conclude that parvalbumins generally lack posttranslational modifications. alpha and beta parvalbumins were differently expressed in human tissues when analyzed by immunoblotting and polymerase-chain-reaction techniques. Whereas alpha parvalbumin was found in a number of adult human tissues, beta parvalbumin was restricted to preterm placenta. The pattern of alpha parvalbumin expression also differs in man compared to other vertebrates. For example, in rat, alpha parvalbumin was found in extrafusal and intrafusal skeletal-muscle fibres whereas, in man, alpha parvalbumin was restricted to the muscle spindles. Different functions for alpha and beta parvalbumins are discussed.
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Affiliation(s)
- U G Föhr
- Department of Pediatrics, University of Zurich, Switzerland
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17
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Henzl MT, Serda RE, Boschi JM. Identification of a novel parvalbumin in avian thymic tissue. Biochem Biophys Res Commun 1991; 177:881-7. [PMID: 2049108 DOI: 10.1016/0006-291x(91)91872-a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A novel calcium-binding protein has been isolated from chicken thymus tissue. Its molecular weight (approximately 11,500) and characteristic interactions with Tb3+ and Eu3+ identify the protein as a member of the parvalbumin family. Electrophoretically distinct from both chicken (muscle) parvalbumin and avian thymic hormone, it represents the third parvalbumin to be identified in avian tissues and the second to be identified in the avian thymus gland.
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Affiliation(s)
- M T Henzl
- Department of Chemistry, New Mexico State University, Las Cruces 88003
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18
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Ahmed FR, Przybylska M, Rose DR, Birnbaum GI, Pippy ME, MacManus JP. Structure of oncomodulin refined at 1.85 A resolution. An example of extensive molecular aggregation via Ca2+. J Mol Biol 1990; 216:127-40. [PMID: 2231727 DOI: 10.1016/s0022-2836(05)80065-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The crystal structure of oncomodulin, a 12,000 Mr protein isolated from rat tumours, has been determined by molecular replacement using the carp parvalbumin structure as a starting model. Refinement was performed by cycles of molecular fitting and restrained least-squares, using area-detector intensity data to 1.85 A resolution. For the 5770 reflections in the range 6.0 to 1.85 A, which were used in the refinement, the crystallographic R-factor is 0.166. The refined model includes residues 2 to 108, three Ca2+ and 87 water molecules per oncomodulin molecule. The oncomodulin backbone is closely related to that of parvalbumin; however, some differences are found after a least-squares fit of the two backbones, with root-mean-square (r.m.s.) deviations of 1 to 2 A in residues 2 to 6, 59 to 61 of the CD loop, 87, 90 and 108. The overall r.m.s. deviation of the backbone residues 5 to 108 is 0.62 A. Each of the two Ca2+ atoms that are bound to the CD and EF loops is co-ordinated to seven oxygen atoms, including one water molecule. The third Ca2+ is also seven-co-ordinated, to five oxygen atoms belonging to three different oncomodulin molecules and to two water molecules which form hydrogen bonds to a fourth oncomodulin; thus, this intermolecular Ca2+ and its equivalents interlink the molecules into zigzag layers normal to the b axis with a spacing of b/2 or 32.14 A. No such extensive molecular aggregation has been reported for any of the related Ca-binding regulatory proteins of the troponin-C family studied thus far. The Ca-O distances in all three polyhedra are in the range 2.07 A to 2.64 A, indicating tightly bound Ca polyhedra.
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Affiliation(s)
- F R Ahmed
- Division of Biological Sciences, National Research Council of Canada, Ottawa
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Hutnik CM, MacManus JP, Banville D, Szabo AG. Comparison of metal ion-induced conformational changes in parvalbumin and oncomodulin as probed by the intrinsic fluorescence of tryptophan 102. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)38419-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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