Carp Muscle Calcium-binding Protein

Peptide separations on substituted polystyrene resins. Effect of cross-linkage

The effect of copolymer cross-linkage on the resolution of soluble tryptic peptides of human globin (alpha- and beta-chains) separated in columns containing substituted polystyrene resin classified to 11 +/- 1 micrometer has been examined. With both the cation and anion exchange resins, polymers of lower cross-linkage provided better resolution; inferior resolution was obtained with 12% cross-linked resins. It was also observed that microparticle anion-exchange resins could be used in columns maintained at 55 degrees instead of 35 degrees as used traditionally. Resolution and yield with 20 x 1 cm resin beds were generally as good as or superior to much longer columns of crushed bead resin of the same chemical structure.

Structure and evolution of calcium-modulated proteins

This review suggests that the intracellular functions of calcium are best understood in terms of calcium's functioning as a second messenger. Further, when functioning as a second messenger, calcium completes its mission not by transferring charge nor by binding to lipid but by binding to specific targets, calcium-modulated proteins. This concept is broadly interpreted to include proteins involved in calcium transport. There is strong evidence that many, if not all, of these calcium-modulated proteins are homologs. Their structures and properties are contrasted to those of extracellular calcium-binding proteins which are not homologous to one another or to the intracellular calcium-modulated proteins. Finally, this line of thought leads to a suggestion of the evolutionary reason for the choice of calcium as the sole inorganic second messenger.

Lanthanide ion probes of structure in biology. Environmentally sensitive fine structure in laser-induced terbium(III) luminescence

The 488 nm line of the CW argon ion laser provides a convenient visible source for the direct excitation of the emissive 5D4 state of the Tb(III) ion. Room temperature emission spectra of Tb(III) in a variety of environments have been examined under relatively high resolution. The samples studied include structurally well-characterized crystalline solids, model chelate complexes in solution and Tb(III) bound to the enzyme thermolysin and the protein parvalbumin. The fine structure in the emissions is caused by ligand field splittings of both ground and excited state J manifolds. These spectra provide signatures sensitive to the immediate coordination environment of the Tb(III) ion. Solid state/solution state structural comparisons are made. The emission fine structure reveal differences between the EF side calcium-binding sites of parvalbumin and the calcium site 1 of thermolysin.

Lanthanides as probes for calcium in biological systems

Calcium ion plays an essential role in many biological processes. The environment about Ca2+may be probed by substitution of tripositive lanthanide ions, Ln3+. Ca2+proteins fall into two broad classes: those that are inhibited by Ln3+substitution and those that are not. It is suggested that although Ca2+undertakes a primarily structural role in the Ln3+non-inhibited proteins, Ca2+may be near the active site or participate in the mechanism of action of Ln3+inhibited proteins. Ca2+and Ln3+radii are similar; most Ln3+are slightly larger than Ca2+in complexes of the same coordination number, and substitution of Ln3+for Ca2+is accommodated by a slight decrease in bond distance or by an increase in coordination number. Luminescence from Tb3+has been demonstrated to be a sensitive environmental probe of Ca2+binding sites in proteins.

Polymorphism of parvalbumins and tissue distribution: characterization of component I, isolated from red muscles of Cyprinus carpio L

The component I isolated from carp red muscle has been characterized as a true parvalbumin, fairly different from carp parvalbumins described so far. The protein is antigenically related to the parvalbumin III from pike, which belongs to the so called parvalbumin lineage alpha. Immunological investigations on the location of the various carp parvalbumins reveal genuine variation in the pattern of these proteins according to organ and type of muscular tissue.

The amino-acid sequence of the major parvalbumin from thornback-ray muscle

The primary structure of the major parvalbumin (pI = 4.45) from the cargilagenous fish Raja clavata has been determined. The amino acid sequence was deduced by the analysis of peptides derived from tryptic digestion of the oxidized protein. These peptides were aligned by comparison with (a) overlapping peptides produced by limited tryptic and chymotryptic digestion, and (b) by comparison with the known structures of other fish parvalbumins. The molecular evolution of thornback ray parvalbumin is briefly discussed.

Preparation and properties of carp muscle parvalbumin fragments A (residues 1 leads to 75) and B (residues 76 leads to 108)

The calcium-binding protein (parvalbumin), isolated from carp (Cyprinus carpio) muscle, has been specifically fragmented into two polypeptides by tryptic hydrolysis at the single arginine residue at position 75. Fragment A contains residues 1 leads to 75 and fragment B is composed of residues 76 leads to 108. The fragments have been characterized according to size, amino acid composition, carboxyl- and aminoterminal analysis. Both fragments appear to be homogeneous by these criteria. The intact protein is known to bind 2 mol of calcium per mol of parvalbumin, and although each fragment alone contains all of the essential ligands for the coordination of one Ca2+, neither fragment displays calcium binding activity. Attempts to reconstitute the two fragments, under a variety of conditions, into a functional complex which can bind calcium have been unsuccessful. The side chain of Arg-75 is known to occupy an internal position in the crystalline structure of parvalbumin (Kretsinger, R.H. and Nockolds, C.E. (1973) J. Biol. Chem. 248, 3313), where it is stabilized by an intricate network of hydrogen bonding involving the side chain of Glu-81. Although this internal salt bridge is approx. 20 A from either calcium binding site, it has been suggested that this structural feature of the molecule plays an essential role in the reversible binding of Ca2+. That the side chain of Arg-75 likewise occupies an internal position in the solution structure is indicated by its unavailability for reaction with 1,2-cyclohexanedione under conditions of physiological pH and temperature. However, in the presence of EDTA and at pH 8, it is readily modified by cyclohexanedione. This modification is accompanied by a concomitant loss in calcium binding activity. Reversal of the modification by treatment with hydroxylamine is accompanied by restoration of calcium binding activity. The serum of these data support the hypothesis that Arg-75 plays a critical role in the structural organization and calcium binding activity of the molecule, and in addition, suggests that the integrity of the peptide bond between Arg-75 and Ala-76 may be necessary for establishing the proper micro-environment required for formation of the internal salt bridge between Arg-75 and Glu-81.

Detecting evolutionary trends from molecular data. 1. Some measures of compositional nonrandomness

The measures of compositional nonrandomness to be discussed as to their physical significance and to their power of detecting evolutionary significant variations are (see article)(pi a priori probability for amino acid i, ni its number of occurrences in a protein of length L). As a concrete example, the pi are here supposed to represent equal frequencies of all non-stop codons. For each quantity, four levels are defined: The base level, with optimal (i.e. minimal nonrandomness) composition, admitting non-integer values of ni; the integer level with optimal integer composition; the noise level, represented by a typical random cain; and the real protein level. On all these levels, S, which is the measure with the most direct physical sense, shows the smoothest behavior with the smallest relative fluctuations and thus the highest resolution.

The amino-acid sequence of the most acidic major parvalbumin from frog muscle

The primary structure of the most acidic (pI - 4.50) of the two major parvalbumins from frog (Rana esculenta) has been determined from a study of its trypsic peptides and of overlapping peptides generated by limited trypsic digestion, chymotrypsic digestion and N-bromosuccinimide cleavage of the protein. The amino acid sequence so obtained is considered in comparison with those known for other parvalbumins and for rabbit troponin-C.

The primary structure of allergen M from cod

The complete primary structure of allergen M of cod (Gadus callarias L.) is presented. The amino acid sequence of fragment TM1, the NH2-terminal peptide of allergen M, was elucidated by the dansyl-Edman method. It consists of 75 amino acids and 1 glucose residue (mol. wt. 8,492). By summation of the sequence data of fragment TM1 and the previously reported fragment TM2, the intact allergen M has 113 residues (mol. wt. 12,328). Fragment TM1 of cod shows less homology (30.6 percent) with the corresponding fragments of other reported fish species than does fragment TM2 (42.1 percent); the intact allergen M shows 34.5 percent homology. The single half cystine of allergen M was shown to be blocked. Gas chromatographic analysis of the reduced and nonreduced allergen M suggested that the glucose is bound to Cys 18 through an S-glucosidic bond.