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At least 19 recordsLinked to original sources
PubMed1992

Crystal structure of the unique parvalbumin component from muscle of the leopard shark (Triakis semifasciata). The first X-ray study of an alpha-parvalbumin.

The three-dimensional structure of parvalbumin from leopard shark (Triakis semifasciata) with 109 amino acid residues (alpha-series) is described at 1.54 A resolution. Crystals were grown at 20 degrees C from 2.9 M-potassium/sodium phosphate solutions at pH 5.6. The space group is P3(1)21 and unit cell dimensions are a = b = 32.12 A and c = 149.0 A. The structure has been solved by the molecular replacement method using pike 4.10 parvalbumin as a model. The final structure refinement resulted in an R-factor of 17.3% for 11,363 independent reflections at 1.54 A resolution. The shark parvalbumin shows the main features of all parvalbumins: the folding of the chain including six alpha-helices, the salt bridge between Arg75 and Glu81, and the hydrophobic core. Compared to the structure of beta-parvalbumins from pike and carp, one main difference is observed: the chain is one residue longer and this additional residue, which extends the F helix, is involved through its C-terminal carboxylate group in a network of electrostatic contacts with two basic residues, His31 in the B helix and Lys36 in the BC segment. Furthermore, hydrogen bonds exist between the side-chains of Gln108 (F helix) and Tyr26 (B helix). There is therefore a "locking" of the tertiary structure through contacts between two sequentially distant regions in the protein and this is likely to contribute to making the stability of an alpha-parvalbumin higher in comparison to that of a beta-parvalbumin. The lengthening of the C-terminal F helix by one residue appears to be a major feature of alpha-parvalbumins in general, owing to the homologies of the amino acid sequences. Besides the lengthening of the C-terminal helix, the classification of the leopard shark parvalbumin in the alpha-series rests upon the observation of Lys13, Leu32, Glu61 and Val66. As this is the first crystal structure description of a parvalbumin from the alpha-phylogenetic lineage, it was hoped that it would clearly determine the presence or absence of a third cation binding site in parvalbumins belonging to the alpha-lineage. In beta-pike pI 4.10 parvalbumin, Asp61 participates as a direct ligand of a third site, the satellite of the CD site. In shark parvalbumin, as in nearly all alpha-parvalbumins, one finds Glu at position 61. Unfortunately, the conformation of the polar head of Glu61 cannot be inferred from the X-ray data.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1979

Chicken parvalbumin. Comparison with parvalbumin-like protein and three other components (Mr = 8,000 to 13,000).

Procedures for a rapid isolation and purification of parvalbumin (Mr = 12,600), parvalbumin-like protein (Mr = 12,800), and three other polypeptides with molecular weights of 12,400 (Component 1), 11,700 (Component 2), and 8,000, respectively, from chicken leg muscle, are described. A direct comparison of parvalbumin with these other proteins showed distinct differences in the amino acid compositions, charge, and immunological behavior. Parvalbumin has two high affinity sites for Ca2+ with a KDiss less than or equal to 10(-6) M (Blum, H. E., Lehky, P., Kohler, L., Stein, E.A., and Fischer, E. H. (1977) J. Biol. Chem. 252, 2834-2838), in contrast to parvalbumin-like protein. Components 1 and 2, and the Mr = 8,000 protein, where only low affinity sites for Ca2+ could be detected (KDiss greater than 10(-3) M). From our results it is concluded that the co-extracted proteins do not constitute isoproteins of parvalbumin. The very low affinity for Ca2+ suggests that these proteins are not involved in processes of Ca2+ transport or Ca2+ regulation as proposed for parvalbumin. Parvalbumin could not be localized within isolated myofibrils and also did not accumulate in primary myogenic cell cultures together with proteins forming the myofibrillar structure. Parvalbumin was not even detected in myotubes in which myofibrils and sarcoplasmatic reticulum were already assembled and functioning. Parvalbumin (or cross-reacting material) was detected in leg muscle and brain 1 day after hatching of the chick. Possible roles for parvalbumin are discussed.

Aging↗
PubMed1984

Amino acid sequences of lower vertebrate parvalbumins and their evolution: parvalbumins of boa, turtle, and salamander.

One major parvalbumin each was isolated from the skeletal muscle of two reptiles, a boa snake, Boa constrictor, and a map turtle, Graptemys geographica, while two parvalbumins were isolated from an amphibian, the salamander Amphiuma means. The amino acid sequences of all four parvalbumins were determined from the sequences of their tryptic peptides, which were ordered partially by homology to other parvalbumins. Phylogenetic study of these and 16 other parvalbumin sequences revealed that the turtle parvalbumin belongs to beta lineage, while the salamander sequences belong, one each, to the alpha and beta lineages defined by Goodman and Pechère (1977). Boa parvalbumin, however, while belonging to the beta lineage, clusters within the fish in all reasonably parsimonious trees. The most parsimonious trees show many parallel or back mutations in the evolution of many parvalbumin residues, although the residues responsible for Ca2+ binding are very well conserved. These most parsimonious trees show an actinopterygian rather than a crossoptyrigian origin of the tetrapods in both the alpha and beta groups. One of two electric eel parvalbumins is evolving more than 10 times faster than its paralogous partner, suggesting it may be on its way to becoming a pseudogene. It is concluded that varying rates of amino acid replacement, much homoplasy, considerable gene duplication, plus complicated lineages make the set of parvalbumin sequences unsuitable for systematic study of the origin of the tetrapods and other higher-taxa divergence, although it may be suitable within a genus or family.

Amino Acid Sequence↗
PubMed1991

Parvalbumin isoforms in chicken muscle and thymus. Amino acid sequence analysis of muscle parvalbumin by tandem mass spectrometry.

Parvalbumins are high-affinity Ca(2+)-binding proteins characterized by an EF-hand structure. Muscles of lower vertebrates contain up to five isoparvalbumins whereas higher vertebrates were believed to contain only one isoform per species. Recently Brewer et al. [Brewer, J.M., Wunderlich, J.K., & Ragland, W. (1990) Biochimie 72, 653-660] purified and sequenced a protein that they named avian thymic hormone, from chicken thymus. This protein, promoting immunological maturation of bone marrow cells in culture, was identified as a parvalbumin. The amino acid composition of this thymic parvalbumin was, however, considerably different from those of chicken muscle parvalbumin [Strehler, E.E., Eppenberger, H.M., & Heizman, C.W. (1977) FEBS Lett. 75, 127-133], suggesting the existence of two tissue-specific parvalbumins in chicken. We purified parvalbumin from chicken muscle, determined its complete amino acid sequence by tandem mass spectrometry, and showed that this protein is rather homologous to muscle parvalbumins from other species but different in 45 positions from the thymic parvalbumin. We discuss the possibility that a parvalbumin gene family might exist in higher vertebrates, expressed in a tissue-specific and developmentally regulated manner.

Amino Acid Sequence↗
PubMed1986

1H NMR spectroscopic studies of calcium-binding proteins. 3. Solution conformations of rat apo-alpha-parvalbumin and metal-bound rat alpha-parvalbumin.

Lacking the extraordinary thermal stability of its metal-bound forms, apo-alpha-parvalbumin from rat muscle assumes two distinct conformations in aqueous solution. At 25 degrees C, its highly structured form predominates (Keq = 5.7; delta G degree = -4.3 kJ X mol-1); as deduced from both 1H NMR and circular dichroism (CD) spectroscopy, this conformation is exceedingly similar to those of its Mg(II)-, Ca(II)-, and Lu(III)-bound forms. The temperature dependences of several well-resolved aromatic and upfield-shifted methyl 1H NMR resonances and several CD bands indicate that the native, highly helical structure of rat apo-alpha-parvalbumin is unfolded by a concerted mechanism, showing no indication of partially structured intermediates. The melting temperature, TM, of rat apo-alpha-parvalbumin is 35 +/- 0.5 degrees C as calculated by both spectroscopic techniques. By 45 degrees C, rat apo-alpha-parvalbumin unfolds entirely, losing the tertiary structure that characterizes its folded form: not only are the ring-current-shifted aromatic and methyl 1H NMR resonances leveled, but the 262- and 269-nm CD bands are also severely reduced. As judged by the decrease in the negative ellipticity of the 222-nm CD band, this less-structured form of rat apo-alpha-parvalbumin shows an approximate 50% loss in apparent alpha-helical content compared to its folded state. Several changes in the 1H NMR spectrum of rat apo-alpha-parvalbumin were exceptionally informative probes of the specific conformational changes that accompany metal ion binding and metal ion exchange. In particular, the line intensities of the ortho proton resonance of Phe-47, the unassigned downfield-shifted alpha-CH resonances from the beta-sheet contacts between the metal-binding loops, the C2H resonance of His-48, and the epsilon-CH3 resonance of an unassigned Met residue were monitored as a function of added metal to determine the stability constants of several metal ion-parvalbumin complexes. We conclude that Mg(II) binds to the CD and EF sites independently, its affinity for the EF site being almost twice that for the CD site. Mg(II)----Ca(II) exchange showed that the CD-site Mg(II) is displaced first, in contrast to Lu(III)'s preferential displacement of the EF-site Ca(II) as determined from the Ca(II)----Lu(III) exchange experiments.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1986

Cation binding to parvalbumin studied by 113Cd and 23Na NMR. Peak assignment of rabbit (pI 5.5) parvalbumin.

Cation binding to three apoparvalbumins was studied by means of 113Cd NMR. The 3 parvalbumins that were investigated were carp pI 4.25, rabbit pI 5.5 and pike pI 5.0. The results showed that Cd2+ ions bind to the EF and CD sites of carp apoparvalbumin pI 4.25 with about the same affinity. For rabbit (pI 5.5) apoparvalbumin, Cd2+ binds preferentially to the EF site, while for pike (pI 5.0) apoparvalbumin, it was the CD site that exhibited somewhat higher affinity for Cd2+. The effect of Mn2+ on the 113Cd signals of rabbit parvalbumin was used to assign the 113Cd NMR signals to the EF and CD sites. The Mn2+ paramagnetic effect on rabbit and pike parvalbumins differed from that obtained for carp parvalbumin. This is in agreement with the assumption that the beta-lineage parvalbumins possess a third external site of higher affinity than the alpha-lineage parvalbumins. Furthermore, 23Na NMR was used to study Na+-Mg2+ competition in the native carp (pI 4.25) parvalbumin. The results showed that Na+ and Mg2+ compete for the same site, the third external site.

Animals↗
PubMed1994

Refined crystal structure of rat parvalbumin, a mammalian alpha-lineage parvalbumin, at 2.0 A resolution.

We present here the X-ray crystal structure of the rat alpha-parvalbumin from fast twitch muscle. This protein (M(r) 11.8 kDa) crystallizes in space group P2(1)2(1)2(1) with unit cell dimensions of a = 34.3 A, b = 55.0 A, c = 156.1 A and three molecules in the asymmetric unit. The protein structure was solved by the molecular replacement method and has been refined to a crystallographic R-factor [formula: see text] of 0.181 for all reflections with I/sigma(I) > or = 2 (I = intensity) between 8.0 and 2.0 A resolution. The molecules located most easily in the molecular replacement rotation function had lower overall thermal motion parameters and higher numbers of intermolecular crystal packing contacts. The overall fold of the polypeptide chain for the rat alpha-parvalbumin is similar to other known parvalbumin structures (root-mean-square deviations in alpha-carbon atom positions range from 0.60 to 0.87 A). There are two Ca(2+)-binding sites in parvalbumins, and there is some evidence for a third ion-binding site, adjacent to the CD site, in the rat species. The level of structural variability among the best-ordered regions of the three independent rat alpha-parvalbumin molecules in the crystallographic asymmetric unit is two to three times higher than the mean coordinate error (0.10 A), indicating flexibility in the molecule. Sequence differences between alpha and beta-lineage parvalbumins result in repacking of the hydrophobic core and some shifts in the protein backbone. The shifts are localized, however, and entire helices do not shift as rigid units.

Animals↗
PubMed1991

Avian thymic hormone and chicken (muscle) parvalbumin are distinct proteins: isolation of a muscle parvalbumin cDNA fragment by PCR.

Access to the nucleotide sequence of parvalbumin from chicken muscle was gained via the polymerase chain reaction. In the absence of specific amino acid sequence data, the PCR primers were based on consensus data for the two parvalbumin Ca2(+)-binding sites. The 137 bp fragment obtained by amplification clearly codes for a parvalbumin, as judged by the presence of 10 invariant codons within the sequence flanked by the primers. When used to probe poly(A)+ RNA from chicken muscle, the fragment recognizes an 800 nucleotide transcript. The translated nucleotide sequence of the muscle protein is unmistakably distinct from that of the thymus-specific parvalbumin known as avian thymic hormone. Of the 31 amplified residues, the two proteins differ at 14. The presence of a distinct parvalbumin in chicken thymus is consistent with the potent effector role proposed for the protein.

Amino Acid Sequence↗
PubMed1991

Ionic interactions with parvalbumins. Crystal structure determination of pike 4.10 parvalbumin in four different ionic environments.

The crystal structure of the Ca-loaded form of pike 4.10 parvalbumin (minor component from pike muscle belonging to the beta phylogenetic series), with both its primary sites CD and EF occupied by Ca2+ ions and its third site occupied by an ammonium ion, as previously determined at 1.93 A resolution, has now been refined to a resolution of 1.65 A. The crystallization of this parvalbumin in different ionic environments has allowed three novel non-isomorphous crystalline forms to be obtained: (1) a first form, crystallized in the presence of a mixture of ammonium sulphate and manganese sulphate, for which all the cation binding sites in the protein are occupied by Mn2+; (2) a second form crystallized in the presence of MgSO4 as the precipitating agent, only differs from the Ca/NH4 form by the occupation of the third site by Mg2+, whereas the primary sites remain occupied by Ca2+; (3) a third form, also crystallized in the presence of MgSO4, corresponds to a well-defined molecular species with both the primary EF site and the third site occupied by Mg2+, whereas the primary CD site remains occupied by CA2+. The corresponding molecular structures reported here have been determined at resolutions between 1.8 and 2.4 A. The comparison of the different crystal structures allows the structural modifications accompanying the substitution of the primary sites by cations differing significantly in their ionic radii (Ca2+, Mn2+, Mg2+) to be investigated in detail, and it also leads to a precise description of the third site in a typical beta parvalbumin. The substitution Ca2+ by Mg2+ within the primary site EF is characterized by a "contraction" of the co-ordination sphere, with a decrease of the mean oxygen-metal distance by a value of 0.25 A and a decrease of the co-ordination number from 7 to 6, as a consequence of the loss of a bidentate ligand (Glu101), which becomes a monodentate one. Such an adaptation of the co-ordination sphere around a cation of smaller size involves, among others, the transformation of the Glu101 side-chain from the stable gauche(+) form to the less stable gauche(-) form. The third site is clearly described as a satellite of the CD primary site, since both sites possess common protein ligands, such as Asp53 and Glu59. Furthermore, Asp61 appears as a specific ligand of the third site in the different environments investigated in this work. We finally discuss the relevance of the third site to parvalbumin phylogeny.

Ammonia↗
PubMed1982

Isolation of neuronal parvalbumin by high-performance liquid chromatography. Characterization and comparison with muscle parvalbumin.

Neuronal parvalbumin has been isolated from rat brain and purified to homogeneity by high-performance liquid chromatography (HPLC) on reverse-phase supports. This procedure includes four consecutive chromatographic steps with an overall protein recovery of 74% and a 26 400-fold purification. The concentration of parvalbumin was found to be approximately 10 mg/kg wet weight in brain tissue, which is about 100 times lower than that in rat muscle. The physical properties of brain parvalbumin are described and compared with those of the muscle counterpart. These proteins were identical in their molecular weights (12 000), isoelectric points (4.9), retention times on C-18 reverse-phase HPLC columns, Ca2+ content (two per molecule), amino acid compositions, and immunological properties. A comparison of the tryptic peptide maps of brain and muscle parvalbumin by analytical HPLC also revealed identity and showed that the isolation method described here did not alter the chemical structure of the protein.

Animals↗
PubMedDate not supplied

[Ca-inhibited binding of melittin with parvalbumin. A new role for parvalbumins?].

It was found that pike parvalbumins pI 4.2 and 5.0 bind amphiphilic peptide melittin extracted from bee venom in an extraordinary Ca-dependent manner: in apo-state the protein forms a tight equimolar complex with melittin (Ka = 10(6) M-1 at 18 degrees C); in Ca- (and Mg-) loaded state it does not take place. Heating of the protein up to temperatures above the denaturation temperature of apo-parvalbumin does not change the stoichiometry of the complex but increases its association constant by an order of magnitude (Ka = 1.2.10(7) M-1 at 44 degrees C). Isolated Ca-binding domain of parvalbumin, 38-108, retains the ability for Ca-inhibited binding of equimolar quantities of melittin. The possible function of parvalbumin in vivo is suggested: Ca-inhibited interactions with some intracellular components.

Animals↗
PubMed1979

Conformational studies on muscular parvalbumins cooperative binding of calcium (II) to parvalbumins.

1H NMR and ORD were used to characterize the respective variations of tertiary structure and secondary structure of parvalbumins with calcium content ((Pa(O), without calcium and PaCa2 calcium saturated) and temperature. It has been observed that the tertiary structure can be lost without significant variation of the helical content. Cooperative binding of calcium to Pa(O) has been shown by NMR spectroscopy under low ionic strength conditions and at neutral pH. The present study shows that the calcium binding affinity of parvalbumin is dependent on the tertiary structure. Calcium binding and calcium release functions of parvalbumins in the muscle may be controlled by their tertiary structure.

Animals↗
PubMed1975

The structure and evolution of parvalbumins. I. Amino acid compositional studies of parvalbumins from four perciform species.

1. Parvalbumins were isolated from the white muscle of Cynoscion regalis, Leiostomus xanthurus, and Menticirrhus americanus of the Sciaenidae and Pomatomus saltatrix of the Pomatomidae. 2. Menticirrhus contains three isoparvalbumins. The other species contain two isoparvalbumins which are designated "fast" and "slow" in accord with their electrophoretic mobilities. Measurements of the denatured molecular weights show the "slow" isoparvalbumins have slightly larger apparent molecular weights, but all apparent molecular weights are in the range 10,400-14,000. 3. Amino acid compositional studies indicate that the fast and slow isoparvalbumins in these fish represent two distinct evolutionary lineages which appear to be evolving at different rates.

Amino Acids↗
PubMed1995

Localization of the Ca(2+)-binding alpha-parvalbumin and its mRNA in epiphyseal plate cartilage and bone of growing rats.

This study describes the localization of alpha-parvalbumin, in undecalcified tibial epiphyseal cartilage and bone of growing rats by immunocytochemistry in the light microscope, and of parvalbumin mRNA by in situ hybridization. They were compared to the distribution of the calbindin-D9K and its mRNA in rat epiphyseal cartilage. All the chondrocytes of the epiphyseal cartilage were parvalbumin-immunopositive, but there was no parvalbumin immunoreactivity in the uncalcified or calcified extracellular cartilage matrix. The intensity of the immunostaining increased from the resting and proliferative to the mature and hypertrophic chondrocytes, with the greatest intensity in the terminal hypertrophic chondrocytes in the calcifying zone. The parvalbumin immunostaining was located in the cytoplasm, but no immunoreactivity was detected in any chondrocyte processes. The parvalbumin mRNA distribution and levels, as revealed by in situ hybridization, exactly mirrored those of the parvalbumin protein. In contrast to parvalbumin, calbindin-D9K and its mRNA appeared in mature chondrocytes and decreased in hypertrophic up to calcifying chondrocytes. Calbindin-D9K was located in the cytoplasm and all along the cell processes. In bone, the osteoblasts and the osteocytes of trabecular and compact cortical bones were immunoreactive for parvalbumin and contained parvalbumin mRNA. Parvalbumin lay in their cytoplasm, but there was no parvalbumin immunostaining in the extracellular uncalcified or mineralized bone matrix. The long processes of osteocytes, in compact bone only, were parvalbumin immunoreactive. Osteoclasts contained cytoplasmic parvalbumin immunoreactivity. Thus, the pattern of immunoreactive parvalbumin distribution indicates that the protein is not involved in the extracellular mineralization of cartilage and bone matrix. It appears to be associated with specific calcium-related intracellular functions in chondrocytes and in osteoblasts, osteocytes, and osteoclasts. As the highest cytoplasmic concentration of parvalbumin is in the terminal hypertrophic chondrocytes, parvalbumin could act as a calcium buffer to delay the death of chondrocytes. In compact bone, parvalbumin could also have a role throughout the osteocyte processes in regulating the fluxes of calcium ions for mineral homeostatis.

Animals↗
PubMed1996

Dynamics of parvalbumin expression in low-frequency-stimulated fast-twitch rat muscle.

Similar to previous observations in rabbit muscle, chronic low-frequency stimulation suppressed parvalbumin expression in fast-twitch muscles of the rat. In extensor digitorum longus and tibialis anterior muscles, parvalbumin mRNA levels steeply declined with apparent half-lives of approximately 26 h and 45 h, respectively. Measurements of parvalbumin synthesis indicated that the reduction in mRNA was immediately transmitted to the level of translation. Relative parvalbumin synthesis rates decayed with an apparent half-life of approximately 60 h. Both the decrease in parvalbumin mRNA and synthesis considerably preceded the decay of parvalbumin protein. Although parvalbumin synthesis had approached zero in 14-day-stimulated muscles, parvalbumin content started to decrease only after some delay (28-day-stimulated muscles still contained 40-50% of their normal parvalbumin content). The lag time between fully suppressed synthesis and the onset of parvalbumin decay, as well as the stability of parvalbumin against tryptic cleavage in the presence of Ca2+ and Mg2+, indicated proteolysis as an important post-translational control of parvalbumin levels. The decrease in parvalbumin mRNA followed a similar time course as that of the mRNA specific to the fast myosin heavy chain HCIIb. After complete suppression, parvalbumin mRNA reached control levels 4 days after cessation of stimulation, which demonstrates the complete reversibility of the stimulation-induced parvalbumin suppression. These results show that a slow motoneuron-like impulse pattern rapidly silences the parvalbumin gene, thus overriding fast-fiber-type-specific programs of gene expression. Due to posttranscriptional regulation and the stability of parvalbumin, this high responsiveness of adult skeletal muscle to altered neuromuscular activity is more conspicuous at the mRNA level than at the protein level.

Actins↗