The Journal of biological chemistry.
Publisher:
American Society for Biochemistry and Molecular Biology. [New York, NY] : Elsevier Inc. on behalf of American Society for Biochemistry and Molecular Biology (2021)
Frequency: Weekly, 1994-
Country: United States
Language: English
Author(s):
American Society of Biological Chemists., American Society of Biological Chemists., Rockefeller Institute for Medical Research.
Start Year:1905 -
ISSN:
0021-9258 (Print)
1083-351X (Electronic)
1067-8816 (Undetermined)
0021-9258 (Linking)
1083-351X (Electronic)
1067-8816 (Undetermined)
0021-9258 (Linking)
Impact Factor
5.5
2022
| NLM ID: | 341041 |
| (DNLM): | J14380000(s) |
| (OCoLC): | 01782222 |
| Coden: | JBCHA3 |
| LCCN: | 06046735 |
| Classification: | W1 JO564C |
Aromatization of 19-norandrogens by equine testicular microsomes. In the stallion testis, aromatase activity was localized in the microsomal fraction. Androgen aromatization occurred through the loss of 1 beta,2 beta hydrogen atoms and appeared to involve free sulfhydryl groups. A single enzyme system seemed to aromatize androgen and norandrogen at the same rate while having a much lower affinity for norandrogens.
A study of roles of evolutionarily invariant proline 30 and glycine 34 of cytochrome c. The previous studies (Juillerat, M. A., and Taniuchi, H. (1986) J. Biol. Chem. 261, 2697-2711), using a three-fragment complex (1-25)H X (28-38) X (39-104) of horse cytochrome c, have shown that invariant leucine 32 and partially invariant leucine 35, both buried in the interior, exhibit a striking difference in perturbation of binding fragment (28-38) by substitution with isoleucine. Then the idea has been proposed that the energy states of leucine 32, the Met-80-S-heme-Fe bond and other distant residues such as tryptophan 59 would be coupled to generate extra force while leucine 35 would be ...
A study on the role of evolutionarily invariant leucine 32 of cytochrome c. To investigate the role of evolutionarily invariant leucine 32 of horse cytochrome c, analogs of residues 28-38, (28-38), each containing a substituted amino acid at positions 32 or 35 were synthesized using Merrifield's method. Position 35 is leucine in horse cytochrome c but replaced by nonpolar amino acids in some species. The ability of the analogs to bind to the two-fragment complex of ferri- or ferro heme fragment (1-25)H and apofragment (39-104) was measured using gel filtration and equilibrium dialysis. Replacement of leucine 32 with isoleucine, for example, increased the dissociation ...
Complexities in the denaturation of horse metmyoglobin by guanidine hydrochloride. The denaturation of horse metmyoglobin by guanidine hydrochloride was studied at pH 6.4 and 25 degrees C. Measurements of both the peptide circular dichroism and the absorbance in the Soret region suggest that the extent of renaturation strongly depends on the time interval during which the protein is exposed to concentrated solutions of the denaturant. From the equilibrium measurements of the absorption in the Soret region, it is concluded that the unfolding of metmyoglobin is complex. This is further supported by kinetic studies of denaturation which suggest the occurrence of the least four ...
Demonstration of a COOH-terminal extension on equine lutropin by means of a common acid-labile bond in equine lutropin and equine chorionic gonadotropin. The beta subunits of equine lutropin and equine chorionic gonadotropin were incubated in 0.013 N HCl for 30 min at 110 degrees C and separated into two fragments by reverse-phase high performance liquid chromatography. The amino acid and carbohydrate compositions of both fragments from each subunit were analyzed. The results demonstrated that equine lutropin-beta has a glycosylated COOH-terminal extension that differs only in carbohydrate composition from the COOH-terminal portion of equine chorionic gonadotropin-beta. This is the first demonstration of a glycosylated COOH-terminal extension i...
The sequence of equine muscle carbonic anhydrase. The sequence of equine muscle carbonic anhydrase (CA-III) has been determined. The 2 reactive cysteines of the 5 such residues have been localized. A strong sequence homology to other mammalian carbonic anhydrases exists, and 91% of the residues in the equine and bovine muscle forms are identical.
Iron deposition in apoferritin. Evidence for the formation of a mixed valence binuclear iron complex. A preliminary EPR investigation of iron accumulation in apoferritin has identified paramagnetic species generated during the early stage of iron deposition within the apoprotein shell. A featureless resonance at g' = 4.3, attributable to solitary high spin Fe3+ ions bound to the protein, is generated when Fe(II) is added to apoferritin at a level of 0.5 Fe/subunit (12 Fe/molecule) followed by air oxidation. This resonance accounts for 36% of the added iron. The remainder is EPR-silent and is probably present as oligomeric Fe3+ species. The intensity of the g' = 4.3 signal is reduced 3-fold upo...
Inhibition of lipases by proteins. A kinetic study with dicaprin monolayers. We report further investigations on protein inhibition of pancreatic and microbial lipases carried out with the monolayer technique. When beta-lactoglobulin A, melittin, serum albumin, myoglobin, and a protein inhibiting lipase from soybean were preincubated with a dicaprin film at a surface pressure of 35 dynes/cm, no activity was detected with horse pancreatic or Rhizopus delemar lipases. By contrast, Rhizopus arrhizus and Geotrichum candidum lipase activities were not impaired under the same conditions. Experiments using mixed lipid-protein film transfer clearly show that the inhibition of ...
Microheterogeneity of type II cAMP-dependent protein kinase in various mammalian species and tissues. Excluding autophosphorylated species, at least six forms of the regulatory subunit of type II cAMP-dependent protein kinase (RII) from various mammalian tissues were identified by sodium dodecyl sulfate (SDS) gel electrophoresis of purified samples and of crude preparations photoaffinity labeled with 8-azido[32P] cAMP and by gel filtration. After autophosphorylation some heart RII forms termed type IIA (bovine, porcine, equine, and dog) shifted to a more slowly migrating band on SDS gels while others termed type IIB (rat, guinea pig, rabbit, and monkey) did not detectably shift. Both subclasse...
Antigenic variation during persistent infection by equine infectious anemia virus, a retrovirus. The recurrent nature of equine infectious anemia has been attributed to relatively rapid antigenic variations in equine infectious anemia virus (EIAV) during persistent infection under selective immune pressures. This model was tested by serological and biochemical analysis of virus isolates recovered from separate febrile episodes in two experimentally infected ponies. Neutralization assays employing immune sera from the experimentally infected ponies demonstrated that distinct antigenic strains of virus predominate during sequential febrile episodes in a single pony. Analysis of the test str...
Ascorbate reduction of horse heart cytochrome c. A zero-energy reduction reaction. The ascorbate reduction of horse heart ferricytochrome c in 0.05 M phosphate + 0.25 M sodium sulfate, at pH 7.3, as a function of temperature, 12-36 degrees C, and at alkaline pH 8.4 using stopped flow technique has been examined. The data have been analyzed in terms of a two-step mechanism, binding followed by reduction (Myer, Y.P., Thallam, K.K., and Pande, A. (1980) J. Biol. Chem. 255, 9666-9673). At neutral pH and up to about 26 degrees C, the first order reduction constant is independent of temperature, i.e. with zero or near-zero activation energy. At higher temperatures, it becomes temp...
Purification of lutropin and follitropin in high yield from horse pituitary glands. A method has been developed for the purification of equine lutropin (eLH) and equine follitropin (eFSH) from horse pituitary glands which attains high yields of both hormones in contrast to previous methods that were devoted to one or the other with inferior recovery of the hormones. Two-pass chromatography over CM-Sephadex was used to separate eLH from eFSH. Subsequent steps employing QAE (quaternary amino-ethyl)-Sephadex chromatography and gel filtration on Sephacryl S-200 produced highly purified hormone preparations. Yields of purified eLH and eFSH were 110 and 60 mg/kg of frozen pituitari...
Comparison of solution and crystalline state protein structures. Photoacoustic study of horse and human hemoglobins. In an effort to assess the influence that crystallization may have on protein conformations, optical absorption spectra of crystalline state hemoglobin derivatives have been examined. These spectra were obtained from photoacoustic spectra using a computer-assisted analysis. Comparisons of crystal and solution state hemoglobins using crystal minus solution state difference spectra indicate that the conformations of these proteins are similar in both states. Crystallization does not change the absorption properties of horse oxyhemoglobin or the cyanide and azide adducts of horse and human methem...
The mechanism of Na+-L-lactate cotransport by brush-border membrane vesicles from horse kidney. Analysis by isotopic exchange kinetics of a sequential model and stoichiometry. The present study determines the characteristics of isotopic Na and lactate exchange under equilibrium conditions in horse kidney brush-border membrane vesicles. The influence of one solute (Na+ or lactate) on the isotopic exchange of the co-transported species (lactate or Na) was analyzed in detail. Analysis of the data suggests that Na and lactate interact sequentially with the carrier. The observed apparent symmetry between the activating effect of low Na concentrations and the inhibiting effect of high Na concentrations on the lactate exchange process suggests that the carrier functions ac...
A distinct environment for iron (III) in the complex with horse spleen apoferritin observed by x-ray absorption spectroscopy. Cell-specific variations in apoferritin structure correlate with variations in iron metabolism that suggest functional specificity of the protein shell. Using EPR spectroscopy, we previously showed that vanadyl binds to specific sites on apoferritin, and that VO2+ binding is reduced by Fe(II) and Fe(III) (the natural substrates) and by metals known to influence iron storage (Chasteen, N. D., and Theil, E. C. (1982) J. Biol. Chem. 257, 7672-7677). Such observations suggest that the metal-binding site is important to apoferritin function and may define a location where the influence of cell-spec...
Further study of the chemical structure of the equine erythrocyte hematoside containing O-acetyl ester. The chemical structure of an equine hematoside, which contained an ester group and comprised 72% of the total erythrocyte gangliosides, was determined by means of nondestructive and destructive procedures. A 400-MHz nuclear magnetic resonance spectrum of the ganglioside in perdeuterodimethyl sulfoxide demonstrated three protons due to a methyl group of an acetyl moiety, as well as amide and anomeric protons which were compatible with those of the ordinary hematoside. The spin decoupling difference spectroscopy of the ganglioside revealed the presence of the following structures. [formula: see ...
Platelet-activating factor stimulates the phosphatidylinositol cycle. Appearance of phosphatidic acid is associated with the release of serotonin in horse platelets. The addition of platelet-activating factor to horse platelets prelabeled with (32P)orthophosphate induces the rapid formation of [32P]phosphatidic acid. This is subsequently followed by a considerable increase in the labeling of phosphatidylinositol. Activation of the formation of phosphatidic acid by platelet-activating factor is evident at a concentration of 1 nM, is maximal at 0.1 microM, and independent of the presence or absence of plasma in the medium. In horse platelets prelabeled with [14C]arachidonic acid, platelet-activating factor stimulates the rapid formation of [14C]phosphatidic ...
The conformational transition of horse heart porphyrin c. The heme iron of horse heart cytochrome c was selectively removed using anhydrous HF. The product, porphyrin c, exhibits the viscosity, far ultraviolet circular dichroic, and fluorescence properties characteristic for native cytochrome c. However, porphyrin c is more susceptible to denaturation by guanidine hydrochloride and by heat than is the parent cytochrome. All of the conformational parameters of porphyrin c exhibit a common reversible transition centered at 0.95 m guanidine hydrochloride at 23 degrees C and pH 7.0. Guanidine denatured porphyrin c refolds in two kinetic phases having tim...
Primary structure of 3-phosphoglycerate kinase from horse muscle. I. Purification of cyanogen bromide peptides and amino acid sequence of peptide CB5 (104 residues). 3-Phosphoglycerate kinase was isolated from horse muscle and subjected to the action of cyanogen bromide. The resulting peptides were separated using gel filtration combined with either ion exchange chromatography on phosphocellulose in 6 M urea or high voltage paper electrophoresis. The sequence of the largest peptide, CB5, has been determined by a combination of automated and manual Edman degradation carried out on the intact peptide and derivatives obtained by proteolytic digestion. The isolation of two peptides derived from CB5 by cleavage of the bond between Asp109 and Pro110 facilitated ...
Equine follicle-stimulating hormone. Purification, acid dissociation, and binding to equine testicular tissue. A simple method of purification of equine follicle-stimulating hormone is described by which two forms of the hormone are obtained. The acid dissociation of the most active preparation was studied and a pKa of 5.8 was determined at 37 degrees C. This value is 2 pH units higher than that observed for pregnant mare serum gonadotropin suggesting that the binding areas between subunits are not identical in the two hormones. We also describe an homologous radioreceptor assay of equine follicle-stimulating hormone which is highly specific for this hormone in contrast to the heterologous systems desc...
The interaction of equine platelet tropomyosin with skeletal muscle actin. Whereas skeletal muscle tropomyosin binds strongly to muscle F-actin in a buffer containing 30 mM KCl and 1-2 mM free Mg2+, equine platelet tropomyosin only binds stoichiometrically (1 tropomyosin molecule per 6 actin monomers) at higher Mg2+ concentrations (7-8 mM free Mg2+). At low free Mg2+ concentrations (1.5 mM) the binding of the platelet protein is only marginally increased by raising the KCl concentration to an optimal value (0.10-0.20 M). This weaker binding can be attributed to the relatively poor head-to-tail polymerization of platelet tropomyosin and its fewer actin-binding sites. ...
Sequence of the low activity equine erythrocyte carbonic anhydrase and delineation of the amino acid substitutions in various polymorphic forms. the sequence of the low activity form of equine erythrocyte carbonic anhydrase has been determined. The most common electrophoretic form, designated D, has been found to have five substitutions. Amino acid exchanges in the electrophoretic variants known as A1, A2, B, and T have been found at six other positions. The data do not permit calculation of the number of polymorphic forms of this enzyme. The equine D isozyme and the analogous human enzyme are quite homologous, 211 of their 260 residues, or 81%, being identical.
The complete amino acid sequence of horse muscle acylphosphatase. The amino acid sequence of horse muscle acylphosphatase is given in the present paper. The carboxymethylated enzyme consists of a single polypeptide chain of 98 amino acid residues with an acetyl group blocking the NH2 terminus and a tyrosine at the COOH terminus. The calculated molecular weight of the native protein, a mixed disulfide with glutathione, is 11,365. The carboxymethylated protein was cleaved by cyanogen bromide. The three expected fragments were purified; moreover, an additional fragment, derived from a partial failure of cleavage at methionine-24, was purified and characterized....
Assembly of intra- and interspecies hybrid apoferritins. An intraspecies hybrid apoferritin was assembled by mixing subunits of horse heart ferritin, which consists mainly of H-type subunits, and horse spleen ferritin, in which L-type subunits predominate. Interspecies hybrid apoferritins were reconstituted from subunits of human liver-horse spleen ferritins and from rat liver-horse spleen ferritins. All the hybrid ferritins migrated as single zones with electrophoretic mobilities intermediate between those of the parent ferritins. Isoelectric focusing data and immunological patterns were consistent with the view that the reassembled apoferritins we...
Topographic antigenic determinants on cytochrome c. Immunoadsorbent separation of the rabbit antibody populations directed against horse cytochrome. Seven populations of site-specific antibodies were isolated from each of three sera of rabbits immunized against glutaraldehyde-polymerized horse cytochrome c. The antibodies were separated using an immunoadsorption scheme which employed the following cytochromes c: horse, beef, guanaco, rabbit, mouse testicular, pigeon, and the cyanogen-bromide cleaved fragment of the rabbit protein containing residues 1 to 65. The monovalent, antigen-binding fragments of the antibodies (Fab') gave 1:1 stoichiometries with native horse cytochrome c in fluorescence quenching assays. Cross-reactivities with het...
Amino acid sequence of the beta-subunit of the follicle-stimulating hormone from equine pituitary glands. A tentative amino acid sequence of the beta-subunit of equine follicle-stimulating hormone (FSH) was derived from the sequences of tryptic, thermolytic as well as peptic, subtilisin, and chymotryptic peptides. Equine FSH-beta is analogous to human FSH-beta except six amino acid substitutions at positions 12, 16, 21, 62, 108, and 114. The amino acid sequence suggests that the hormone-specific beta-subunits of FSH are similar at the interspecies level, whereas the amino acid sequences of the hormone nonspecific alpha-subunits show variations.
Isolation and amino acid sequence of the alpha-subunit of follicle-stimulating hormone from equine pituitary glands. Six hundred milligrams of follicle-stimulating hormone (FSH), containing 110 NIH-FSH-S1 units/mg, was isolated from 9 kg of equine pituitary glands. The equine FSH was dissociated into alpha- and beta-subunits. A tentative amino acid sequence of the alpha-subunit was determined. The alpha-subunit contained 82 amino acids. The equine FSH-alpha is shorter by 10 to 14 amino acids at the NH2 terminus and has several substitutions at several positions as compared with human FSH-alpha and bovine thyroid-stimulating hormone-alpha. At the intraspecies level, the alpha-subunits of human FSH, human lute...