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1.
Anticancer Res ; 11(3): 1061-4, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1909513

RESUMEN

The effects of lombricine extracted and purified from earthworm (Lumbricus terrestris) skin on the growth of palpable sizes (approximately 5 mm) of spontaneous mammary tumours were studied in SHN mice. In Experiment 1, daily subcutaneous injections of lombricine (0.3 mg/0.05 ml olive oil) inhibited markedly the growth of tumours associated with the retardation of the growth of preneoplastic mammary hyperplastic alveolar nodules. In 1H-NMR spectra, the experimental mice had lower serum levels of lactic acid and glucose than the control. On the other hand, urine of the former group contained higher levels of allantoin, creatine and creatinine than that of the latter. In Experiment 2, lombricine given as diet at the concentration of 120 mg/kg also inhibited the growth of tumours, though to a lesser degree than the injection. The treatment had little effect on 1H-NMR spectra of either serum or urine and normal and preneoplastic mammary gland growth. All results indicate that the inhibition by lombricine of the growth of mammary tumours is at least partly due to the maintenance of homeostasis of the body including the regulation of the excess uptake of glucose as a source of energy and nutrition.


Asunto(s)
Neoplasias Mamarias Animales/tratamiento farmacológico , Serina/análogos & derivados , Animales , Peso Corporal , Endometriosis/tratamiento farmacológico , Femenino , Neoplasias Mamarias Animales/patología , Ratones , Oligoquetos/análisis , Lesiones Precancerosas/patología , Serina/uso terapéutico
2.
Histochemistry ; 95(5): 495-501, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1907955

RESUMEN

BTAN (Sumi Y et al. (1982) Histochemistry 73:481) was investigated as a histochemical Cd/Zn chelator. Cd-BTAN exhibits a main peak about 635 nm, while Zn-BTAN exhibits a main peak about 644 nm. The isobestic wavelength for Cd-BTAN and Zn-BTAN is 638 nm. The microscopical detection limit for Cd is about 25 amol/microns 2, and for Zn about 5 amol/microns 2. The relation between metal and bound chelator is fairly linear at a BTAN concentration more than 10-fold the metal concentration. Histochemical localization was fair to good, with a crystal size of up to 0.2-0.3 micron. The chelate was unaffected by hydrophilic and largely also by hydrophobic mounting media. The original staining procedure proved erratic and was modified. Posttreatment with oxine to selectively demonstrate Cd in the presence of Zn (Sumi Y et al. 1982) seriously reduced the staining intensity. Post-treatment for 8-15 min with HCl, 0.5 mol/l, in 50% ethanol removed Cd-BTAN completely with little reduction of Zn staining intensity, even from sites with 5x as much Cd as Zn. It is concluded that BTAN permits direct quantitative detection of (Zn + Cd). Provided certain precautions are taken quantitative detection of Zn and quantitation of Cd in mixed Zn/Cd sites is possible by microphotometry of the stained section before and after differentiation for 8-15 min with the HCl/50% ethanol medium.


Asunto(s)
Cadmio/análisis , Quelantes , Zinc/análisis , Animales , Compuestos Azo/síntesis química , Benzotiazoles , Quelantes/síntesis química , Oligoquetos/análisis , Espectrofotometría , Tetrahymena pyriformis/análisis
3.
Eur J Biochem ; 194(1): 67-73, 1990 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-2253625

RESUMEN

The extracellular hemoglobin of the aquatic oligochaete Tubifex tubifex consists of four subunits: a monomer of 16.5 kDa, a disulfide-bonded trimer of about 50 kDa and at least two subunits of about 30 kDa. The complete amino acid sequence of the monomeric subunit was determined: it consists of 141 amino acid residues and has a molecular mass of 16,286 Da including a heme group. 39 residues (28%) were found to be identical with those in the corresponding positions in the monomeric globin chains from Lumbricus terrestris, Pheretima sieboldi, and Tylorrhynchus heterochaetus. Tubifex and Lumbricus are most similar, with 75 amino acid identities (53%). There are eight invariant residues amongst these monomeric globins and the intracellular monomeric globin of Glycera and the human beta-globin. The monomeric globin from Tubifex aligns best with those of group A, globins which have a Cys in their second position and an invariant Lys-Val-Lys at positions 9-11 [Gotoh et al. (1987) Biochem. J. 241, 441-445]. The two cysteine residues, at positions 2 and 131, appear to be disulfide-bonded.


Asunto(s)
Hemoglobinas/química , Oligoquetos/análisis , Secuencia de Aminoácidos , Animales , Anélidos/análisis , Cromatografía Líquida de Alta Presión , Datos de Secuencia Molecular , Fragmentos de Péptidos/química , Mapeo Peptídico
4.
Sci Total Environ ; 96(1-2): 121-9, 1990 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2237395

RESUMEN

The concentrations of Cu, Zn, Fe, Mn, Ni, Cd, Pb and Co have been determined in water, bottom sediments, plankton, zoobenthos and ichthyofauna of mesotropic Lake Piaseczno located in eastern Poland. In water, sediments, plankton and benthos the most abundant heavy metals were Fe, Zn and Mn, whereas in fish Zn, Cu, and Mn were most abundant. The amount of heavy metals in the biotic components was dependent upon their concentration in water and partly upon the concentration in bottom sediments. A considerably less important role in the translocation of heavy metals is probably played by trophic interactions.


Asunto(s)
Agua Dulce/análisis , Metales/análisis , Animales , Peces/metabolismo , Oligoquetos/análisis , Plancton/análisis , Polonia
6.
Eur J Biochem ; 185(1): 127-34, 1989 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-2806255

RESUMEN

The giant extracellular hemoglobin of the earthworm Pheretima sieboldi is mainly composed of two heme-containing subunits: a monomer; chain I and a disulfide-bonded trimer of chains II, III and IV. Both subunits can be separated easily by gel filtration under alkaline conditions. The amino acid sequence of chain I has been determined. It is composed of 141 residues, has two half-cystine residues forming a intrachain disulfide bridge, and has a molecular mass of 16911 Da including a heme group. Heterogeneity was found at position 37 (His or Ser). The amino acid sequence of Pheretima chain I showed 30-50% identity with those of eight heme-containing chains of Lumbricus and Tylorrhynchus hemoglobins. The sequences of nine chains of annelid giant hemoglobins were compared separately in the functionally essential central exonic region and structurally essential side exonic regions, and a phylogenetic tree was constructed. The amino acid substitution rate for the central exon was found to be about 1.5 times slower than that for the side exons.


Asunto(s)
Hemoglobinas/análisis , Oligoquetos/análisis , Secuencia de Aminoácidos , Animales , Exones , Hemoglobinas/genética , Datos de Secuencia Molecular , Oligoquetos/clasificación , Filogenia
7.
Histochemistry ; 92(3): 237-41, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2777641

RESUMEN

The elemental compositions of chloragosome 'granules' in the earthworm Lumbricus rubellus living in non-polluted (Dinas Powys) and heavily Pb-polluted (Wemyss) soils were determined by fully quantitative electron probe X-ray microanalysis. P, Ca, S and Zn were the major elemental components of the chloragosomes. High Pb concentrations were found in chloragosomes of Wemyss animals; Pb was not detected in chloragosomes of Dinas Powys animals. Partial correlation and regression analysis indicated that the in vivo accumulation of Pb by chloragosomes was accompanied by diminished chloragosomal Ca concentrations. Pb is bound by P-containing ligand(s) in the chloragosome matrix. The sequestration of Pb by chloragosomes results in the detoxification of the metal by accumulative immobilization.


Asunto(s)
Gránulos Citoplasmáticos/análisis , Plomo/análisis , Oligoquetos/análisis , Animales , Calcio/análisis , Gránulos Citoplasmáticos/ultraestructura , Microanálisis por Sonda Electrónica , Fósforo/análisis , Contaminantes del Suelo/análisis , Azufre/análisis , Zinc/análisis
8.
Arch Biochem Biophys ; 267(2): 459-66, 1988 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3214164

RESUMEN

We have isolated a potent proteinaceous chemoattractant from aqueous washes of earthworm (Lumbricus terrestris) for garter snakes (Thamnophis sirtalis) by means of a covalent chromatography. It contained free sulfhydryl groups and showed an apparent mass of 20 kDa. The chemoattractive activity of this protein could be destroyed by heating as well as by proteolysis. Its activity could also be reversibly blocked by mixed disulfide formation with dithiodipyridine, suggesting that the free sulfhydryl(s) was essential for its function as a chemoattractant. This bioactive material had a tendency to form intermolecular crosslinked aggregates during isolation, if reducing agents were not included. Some of the high-molecular-weight aggregates cochromatographed with earthworm cuticle collagen on Ultragel AcA 34 or 44 columns. In contrast to an earlier report by D. M. Kirschenbaum, N. Schulman, and M. Halpern [1986) Proc. Natl. Acad. Sci. USA 83, 1213-1216) the purified earthworm collagen showed no chemoattractive activity to garter snakes.


Asunto(s)
Factores Quimiotácticos/aislamiento & purificación , Oligoquetos/análisis , Proteínas/aislamiento & purificación , Serpientes , Animales , Cromatografía en Gel , Colágeno/aislamiento & purificación , Electroforesis en Gel de Poliacrilamida , Compuestos de Sulfhidrilo/aislamiento & purificación
9.
Neurochem Res ; 13(9): 893-901, 1988 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2465500

RESUMEN

We report here the isolation of fractions enriched in components of the myelin-like membranes surrounding the giant axons of the earthworm. Lumbricus terrestris L. The composition and purity of the fractions have been assessed using SDS-protein electrophoresis, Western immunoblots, and electron microscopy. Preliminary enzyme assays indicated that the mitochondrial marker, succinate dehydrogenase, has a similar specific activity distribution in earthworm nerve cord and in mouse liver sedimentation velocity fractions, however, the distribution of the total units of activity among the fractions seems to indicate the existence of smaller mitochondria in earthworm nerve cord compared with mouse liver mitochondria. In earthworm nerve cord fractions, Na+/K+ ATPase and Ca2+/Mg2+ ATPase were found to be enriched exclusively in the fraction containing large plasma and myelin-like membranes, while in the mouse liver fractions, the total units of these two enzymes were found to be distributed broadly among fractions. 5'-Nucleotidase activity in the earthworm nerve cord seemed to be restricted to the microsomal fractions (endomembrane network), with a very low activity associated with the large plasma and myelin-like membrane fraction. We have established the presence of keratins or prekeratins in the myelin-like membranes, probably in the form of tonofilaments. However, we could not show that the desmosome-like structures, characteristic of these membranes, are composed of those proteins described for vertebrate epithelial desmosomes.


Asunto(s)
Axones/análisis , Vaina de Mielina/análisis , Oligoquetos/análisis , Animales , Axones/enzimología , Axones/ultraestructura , Queratinas/análisis , Microscopía Electrónica , Vaina de Mielina/enzimología , Vaina de Mielina/ultraestructura , Fracciones Subcelulares/análisis
10.
J Lipid Res ; 29(5): 679-89, 1988 May.
Artículo en Inglés | MEDLINE | ID: mdl-3411242

RESUMEN

The common phospholipids from biological sources were quantitated using phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy in conjunction with an analytical reagent composed of two parts: 1) 2 ml of reagent chloroform in which was dissolved 0.01-100 mg of crude tissue lipid extracted from tissue sources using chloroform-methanol 2:1, the extract having been washed with 0.2 vol. of 0.1 M KCl; 2) 1 ml of an aqueous methanol reagent composed of one part 0.2 M (ethylenedinitrilo)-tetraacetic acid in D2O titrated to pH 6 with CsOH and four parts of reagent methanol. In a magnetic field of 11.75 Tesla, the extracted phospholipids yield narrow signals (1.8-3.2 Hz at half-height), corresponding to each generic species, e.g., phosphatidylcholines, phosphatidylethanolamines, etc., permitting resolution among the various phospholipid families and their lyso and plasmalogen derivatives. The reagent permits assays of high precision and accuracy using a modest amount of NMR spectrometer time (ca. 15 min/assay). The procedures described, which are compared to high-performance liquid chromatography, are convenient for the routine analysis of phospholipids from biological sources.


Asunto(s)
Fosfolípidos/análisis , Animales , Bivalvos/análisis , Cationes , Pollos , Cromatografía Líquida de Alta Presión , Colorimetría , Espectroscopía de Resonancia Magnética/métodos , Miocardio/análisis , Oligoquetos/análisis , Óvulo/análisis , Fósforo/análisis , Ratas , Anémonas de Mar/análisis , Glycine max/análisis , Manejo de Especímenes
12.
Comp Biochem Physiol B ; 91(3): 577-9, 1988.
Artículo en Inglés | MEDLINE | ID: mdl-3233931

RESUMEN

1. The mol. wt of the extracellular haemoglobin of the oligochaete Lumbricus terrestris was determined by counting in negatively stained electron micrographs. 2. The value obtained using apoferritin as a mol. wt standard is (3.8 +/- 0.3) x 10(6), in agreement with recent determinations employing different physical methods. 3. We conclude that all annelid extracellular haemoglobins and chlorocruorins which have the same dimensions as Lumbricus haemoglobin probably have the same mol. wt.


Asunto(s)
Hemoglobinas/ultraestructura , Oligoquetos/análisis , Animales , Apoferritinas/normas , Apoferritinas/ultraestructura , Espacio Extracelular/análisis , Microscopía Electrónica , Peso Molecular
13.
J Biol Chem ; 262(7): 3123-31, 1987 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-3546301

RESUMEN

The giant extracellular hemoglobin (3,800 kDa) of the oligochaete Lumbricus terrestris consists of four subunits: a monomer (chain I), two subunits each of about 35 kDa (chains V and VI), and a disulfide-bonded trimer (50 kDa) of chains II, III, and IV. The complete amino acid sequence of chain I was determined: it consists of 142 amino acid residues and has a molecular weight of 16,750 including a heme group. Fifty-nine residues (42%) were found to be identical with those in the corresponding positions in Lumbricus chain II (Garlick, R. L., and Riggs, A. F. (1982) J. Biol. Chem. 257, 9005-9015); 45 (32%), 56 (40%), 44 (31%), and 45 (32%) residues were found to be in identical positions in the sequences of chains I, IIA, IIB, and IIC, respectively, of Tylorrhynchus heterochaetus hemoglobin (Suzuki, T., and Gotoh, T. (1986) J. Biol. Chem. 261, 9257-9267). When the sequences of all six annelid chains are compared, 18 invariant residues are found in the first 104 residues of the molecule; very little homology exists among the annelid chains in the carboxyl-terminal 38-residue region. Nine of the 18 invariant residues are also found in the human beta-globin chain.


Asunto(s)
Hemoglobinas , Oligoquetos/análisis , Secuencia de Aminoácidos , Animales , Cromatografía Líquida de Alta Presión , Bromuro de Cianógeno , Espacio Extracelular/análisis , Peso Molecular , Fragmentos de Péptidos , Péptido Hidrolasas , Tripsina
14.
Experientia Suppl ; 52: 265-72, 1987.
Artículo en Inglés | MEDLINE | ID: mdl-2959515

RESUMEN

Metallothionein (MT) and the related metal-binding proteins in tissues of lower vertebrates and invertebrates were isolated by gel filtration chromatography (conventional liquid and high performance liquid chromatography). The metal-binding proteins including MT were detected by determining the metals bound to the proteins by atomic absorption spectrophotometry. This analytical procedure was recommendable as the first step to characterize unknown metal-binding proteins in diverse living bodies. As MT in the lower vertebrates, avian (Japanese quail), reptilian (tortoise), amphibian (8 species of frogs and 2 species of tailed amphibians) and fish MTs were isolated and characterized. The number of isoMTs was different among animals belonging not only to different classes but also to different species in the same family. One of the isoMTs in the avian, reptilian and amphibian MTs was shown to contain one histidinyl residue. Cadmium(Cd)-binding proteins were induced in three species of insect (Insecta, Arthropoda) larvae (midge, fleshfly and silkworm) by loading of Cd. Distribution of Cd in insect tissues was different among the three species though the alimentary canal was commonly the most important tissue for the storage of Cd in all species. Further, Cd in the soluble fractions was bound to inducible proteins of different molecular sizes in the three species. Cd-binding protein was also detected in the waterflea (Crustacea, Arthropoda) after loading of Cd. Cd-binding proteins induced in the earthworm (Oligochaeta, Annelida) by loading of Cd were a mixture of proteins with three different molecular sizes. One of the Cd-binding proteins with an apparent molecular size of 7,000 was shown to have characteristics of MT.


Asunto(s)
Invertebrados/metabolismo , Vertebrados/metabolismo , Anfibios , Animales , Artrópodos/análisis , Aves , Cadmio/metabolismo , Crustáceos/análisis , Peces , Metalotioneína/análisis , Oligoquetos/análisis , Reptiles , Especificidad de la Especie
15.
Sci Total Environ ; 55: 321-7, 1986 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-3810135

RESUMEN

In India organochlorine insecticides such as DDT and HCH constitute more than 70% of the pesticides used at present. Its continued use has given interest to monitor for the last few years the extent of organochlorine insecticide residues in soil, water, air and rain water in Delhi area. Out of the 50 samples each of soil and earthworms collected from different parts 48 samples showed that soil and earthworms contained 0-2.61 and 0-37.74 mg Kg-1 of total DDT residues respectively. The area near the vicinity of the DDT factory showed high levels of DDT residues. A two-year survey of the Yamuna river in Delhi showed that water contained an average of 0.24 ug L-1 and the bottom sediment had 0.24 mg Kg-1 of total DDT residues. The fishes collected from the Yamuna river showed very high bioaccumulation of DDT residues. The air and rainwater samples monitored from 3 different areas for two years indicated that DDT was more near the DDT factory area while HCH was more near a commercial complex. These results indicate that the overall organochlorine-residue levels in Delhi is not alarming. It probably indicates that DDT and HCH are more rapidly dissipated and degraded in a tropical country like India.


Asunto(s)
Contaminantes Atmosféricos/análisis , Insecticidas/análisis , Contaminantes del Suelo/análisis , Contaminantes del Agua/análisis , Animales , DDT/análisis , Peces/metabolismo , India , Oligoquetos/análisis
16.
Proc Natl Acad Sci U S A ; 83(21): 8034-8, 1986 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-3464939

RESUMEN

The complete dissociation of the hexagonal bilayer structure of Lumbricus terrestris hemoglobin (3900 kDa) at neutral pH, in the presence of urea, guanidine hydrochloride, sodium perchlorate, potassium thiocyanate, sodium phosphotungstate, and sodium phosphomolybdate, followed by gel filtration at neutral pH on Sephacryl S-200 or Superose 6, produced two fragments, II (65 kDa) and III (17 kDa); NaDodSO4/polyacrylamide gel electrophoresis showed that peak II consisted of subunits D1 (31 kDa, chain V), D2 (37 kDa, chain VI), and T (50 kDa, disulfide-bonded trimer of chains II, III, and IV) and that peak II consisted of subunit M (16 kDa, chain I). When dissociation was incomplete, two additional peaks were present, peak Ia eluting at the same volume as the whole hemoglobin and peak Ib (200 kDa). Scanning transmission electron micrographs of peak Ia showed it to consist of whole molecules and of incomplete hexagonal bilayer structures, missing an apparent 1/12th. Peak Ib contained all four subunits but was usually deficient in subunits D1 and D2, was not always in equilibrium with the whole molecule, and could be dissociated further into II and III. The patterns of dissociation observed at neutral pH were very similar to those observed previously at alkaline pH and at acid pH and appear to be incompatible with the generally accepted multimeric model of Lumbricus hemoglobin subunit structure. A model is proposed in which it is postulated that the stoichiometries of some of the subunits need not be constant and that subunits D1 and D2 either form a "bracelet" decorated with complexes of T and M subunits or serve as "linkers" between the latter, to provide the appearance of a two-tiered hexagonal structure. Additional support for the proposed model comes from observations that the fragment II obtained subsequent to dissociation at pH 4, in sodium phosphotungstate, in sodium perchlorate, and in potassium thiocyanate was found to be in equilibrium with a hexagonal bilayer structure IaR(II), whose dimensions were approximately equal to 20% smaller than those of the native hemoglobin.


Asunto(s)
Hemoglobinas/análisis , Oligoquetos/análisis , Animales , Cromatografía en Gel , Electroforesis en Gel de Poliacrilamida , Concentración de Iones de Hidrógeno , Fragmentos de Péptidos/análisis , Conformación Proteica
18.
J Neurochem ; 45(6): 1875-9, 1985 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-4056795

RESUMEN

As part of a systematic study of the evolution of the nervous system, the lipid composition of the ventral nerves of earthworms was examined. The nerve axons are wrapped in copious layers of loosely bound membrane, superficially resembling the myelin sheath of vertebrates. However, neither galactocerebroside nor sulfatide, both of which are considered to be markers for myelin, was present, and only traces of glucocerebroside, which is abundant in shrimp nerve, were detected. The lipids were rich in cholesterol (15.3 mumol/g of fresh tissue) and phospholipids (21.7 mumol/g of fresh tissue). The phospholipids were composed of phosphatidylethanolamine, -choline, -serine, and -inositol in the ratio of 41:44:8:7. Most of the ethanolamine-containing phospholipids were in the form of plasmalogens. The fatty acid moieties of these phospholipids were predominantly 18:1, 18:0, and 20:1, whereas the aldehyde moieties of plasmalogen were mostly 18:0. Sphingomyelin, which is considered a ubiquitous component of animal membranes, was not detected. How the unique structure of the membranes of earthworm nerves may be related to the function of the nervous system in this organism is discussed.


Asunto(s)
Lípidos/análisis , Sistema Nervioso/análisis , Oligoquetos/análisis , Animales , Cromatografía de Gases , Cromatografía Líquida de Alta Presión , Cromatografía en Capa Delgada , Decápodos , Glucolípidos/análisis , Mamíferos , Ácidos Fosfatidicos/análisis , Fosfolípidos/análisis , Esfingolípidos/análisis
19.
Dev Comp Immunol ; 9(1): 11-20, 1985.
Artículo en Inglés | MEDLINE | ID: mdl-3922817

RESUMEN

A bacteriostatic activity in Eisenia fetida andrei cell free coelomic fluid is described. This activity is detected by growth inhibition of a bacteria Bacillus megaterium. Gel filtration analysis revealed eleven coelomic fluid protein fractions designated A, B,..J. Antibacterial activity was mainly found within fractions B and C. Chromatofocusing resolved fractions B-C into five different peaks named alpha BC, beta BC,... epsilon BC. Antibacterial activity appeared mediated by three different proteins characterized by their molecular weights (20,000, 40,000 and 45,000) and their isoelectric points (4.9, 5.75 and 6.0). These bacteriostatic proteins possess either hemolysis or hemagglutination activities. The polymorphic aspect of this humoral antibacterial defense is discussed.


Asunto(s)
Oligoquetos/análisis , Animales , Bacillus megaterium/crecimiento & desarrollo , Bacillus megaterium/inmunología , Actividad Bactericida de la Sangre , Líquidos Corporales/análisis , Líquidos Corporales/inmunología , Oligoquetos/inmunología , Oligoquetos/microbiología , Proteínas/aislamiento & purificación
20.
J Mol Biol ; 179(4): 713-27, 1984 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-6502714

RESUMEN

The functional properties of erythrocruorin from Octolasium complanatum (a common earthworm of Central Italy) have been characterized in great detail. Special attention has been given to the reciprocal effects of the various ligands, namely oxygen, cations and protons. The data obtained under a variety of experimental conditions bring out the dominant role played by cations in the modulation of both homotropic and heterotropic interactions. In this respect, the most interesting observation concerns the unusual interplay between protons and cations that occurs in this erythrocruorin, the first respiratory pigment in which the Bohr effect is due totally to the O2-linked binding of an allosteric effector. The oxygen binding data collected under the various experimental conditions have been analyzed in terms of a modified two-state model, which takes into account the fact that allosteric effectors may also influence the ligand binding properties of the state that they stabilize. The analysis shows that the number of interacting sites necessary for the observed co-operativity in O2 binding is much smaller than the number of heme groups carried by the whole molecule, in accordance with previous findings on hemocyanins, the other class of giant respiratory pigments. Moreover, the analysis indicates that the dimensions of these "functional constellations" are under the control of allosteric effectors.


Asunto(s)
Eritrocruorinas/metabolismo , Hemoglobinas/metabolismo , Oligoquetos/análisis , Oxígeno/sangre , Regulación Alostérica , Animales , Cationes/farmacología , Concentración de Iones de Hidrógeno , Temperatura , Termodinámica
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