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https://www.readbyqxmd.com/read/27456123/ionic-surfactants-glossoscolex-paulistus-hemoglobin-interactions-characterization-of-species-in-the-solution
#1
Francisco A O Carvalho, Fernanda R Alves, Marcel Tabak
Glossoscolex paulistus hemoglobin (HbGp) is an oligomeric multisubunit protein with molecular mass of 3600kDa. In the current study, the interaction of sodium dodecyl sulfate (SDS) and cetyl trimethylammonium chloride (CTAC) surfactants with the monomer d and the whole oxy-HbGp, at pH 7.0, was investigated. For pure monomer d solution, SDS promotes the dimerization of subunit d, and the monomeric and dimeric forms have sedimentation coefficient values, s20,w, around 2.1-2.4 S and 2.9-3.2 S, respectively. Analytical ultracentrifugation (AUC) and isothermal titration calorimetry (ITC) data suggest that up to 26 DS(-) anions are bound to the monomer...
November 2016: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/27221949/metals-content-of-glossoscolex-paulistus-extracellular-hemoglobin-its-peroxidase-activity-and-the-importance-of-these-ions-in-the-protein-stability
#2
Celia S Caruso, Ezer Biazin, Francisco A O Carvalho, Marcel Tabak, José F R Bachega
In this work we investigate the presence of divalent cations bound to the Glossoscolex paulistus (HbGp) hemoglobin and their effect over the protein stability and the peroxidase (POD) activity. Atomic absorption studies show that the HbGp iron content is consistent with the presence of 144 ions per protein. Moreover, using iron as a reference, the content of calcium was estimated as 30±4 ions per protein, independently of the EDTA pre-treatment or not prior to the acidic treatment performed in the protein digestion...
August 2016: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/27017354/thermal-stability-of-extracellular-hemoglobin-of-rhinodrilus-alatus-hbra-dls-and-saxs-studies
#3
José Wilson P Carvalho, Francisco A O Carvalho, Patrícia S Santiago, Marcel Tabak
Oxy-HbRa thermal stability was evaluated by dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS) at pH 5.0, 7.0, 8.0, and 9.0. DLS results show that oxy-HbRa, at pH 7.0 and 5.0, remains stable up to 56 °C, undergoing denaturation/aggregation in acidic media above 60 °C, followed by partial sedimentation of aggregates. At alkaline pH values 8.0 and 9.0, oxy-HbRa oligomeric dissociation is observed above 30 °C, before denaturation. SAXS data show that oxy-HbRa, at 20 °C, is in its native form, displaying radius of gyration (R g) and particle maximum dimension (D max) of 108 ± 1 and 300 ± 10 Å, respectively...
September 2016: European Biophysics Journal: EBJ
https://www.readbyqxmd.com/read/26574155/interaction-of-cationic-dodecyl-trimethyl-ammonium-bromide-with-oxy-hbgp-by-isothermal-titration-and-differential-scanning-calorimetric-studies-effect-of-proximity-of-isoelectric-point
#4
Fernanda Rosa Alves, Francisco Adriano O Carvalho, José Wilson P Carvalho, Marcel Tabak
In this work, isothermal titration and differential scanning calorimetric methods, in combination with pyrene fluorescence emission and dynamic light scattering have been used to investigate the interaction of dodecyltrimethylammonium bromide (DTAB) with the giant extracellular Glossoscolex paulistus hemoglobin (HbGp) in the oxy-form, at pH values around the isoelectric point (pI ≈ 5.5). Our ITC results have shown that the interaction of DTAB with the hemoglobin is more intense at pH 7.0, with a smaller cac (critical aggregation concentration) value...
April 2016: Biopolymers
https://www.readbyqxmd.com/read/26057666/the-structure-of-the-giant-haemoglobin-from-glossoscolex-paulistus
#5
José Fernando Ruggiero Bachega, Fernando Vasconcelos Maluf, Babak Andi, Humberto D'Muniz Pereira, Marcelo Falsarella Carazzollea, Allen M Orville, Marcel Tabak, José Brandão-Neto, Richard Charles Garratt, Eduardo Horjales Reboredo
The sequences of all seven polypeptide chains from the giant haemoglobin of the free-living earthworm Glossoscolex paulistus (HbGp) are reported together with the three-dimensional structure of the 3.6 MDa complex which they form. The refinement of the full particle, which has been solved at 3.2 Å resolution, the highest resolution reported to date for a hexagonal bilayer haemoglobin composed of 12 protomers, is reported. This has allowed a more detailed description of the contacts between subunits which are essential for particle stability...
June 2015: Acta Crystallographica. Section D, Biological Crystallography
https://www.readbyqxmd.com/read/25546245/denaturant-effects-on-hbgp-hemoglobin-as-monitored-by-8-anilino-1-naphtalene-sulfonic-acid-ans-probe
#6
Ana E B Barros, Francisco A O Carvalho, Fernanda R Alves, José W P Carvalho, Marcel Tabak
Glossoscolex paulistus extracellular hemoglobin (HbGp) stability has been monitored in the presence of denaturant agents. 8-Anilino-1-naphtalene-sulfonic acid (ANS) was used, and spectroscopic and hydrodynamic studies were developed. Dodecyltrimethylammonium bromide (DTAB) induces an increase in ANS fluorescence emission intensity, with maximum emission wavelength blue-shifted from 517 to 493 nm. Two transitions are noticed, at 2.50 and 9.50 mmol/L of DTAB, assigned to ANS interaction with pre-micellar aggregates and micelles, respectively...
March 2015: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/25433131/guanidine-hydrochloride-and-urea-effects-upon-thermal-stability-of-glossoscolex-paulistus-hemoglobin-hbgp
#7
Francisco A O Carvalho, Fernanda R Alves, José W P Carvalho, Marcel Tabak
Glossoscolex paulistus hemoglobin (HbGp) has a molecular mass of 3600kDa. It belongs to the hexagonal bilayer hemoglobin class, which consists of highly cooperative respiratory macromolecules found in mollusks and annelids. The present work focusses on oxy-HbGp thermal stability, in the presence of urea and guanidine hydrochloride (GuHCl), monitored by several techniques. Initially, dynamic light scattering data show that the presence of GuHCl induces the protein oligomeric dissociation, followed by a significant 11-fold increase in the hydrodynamic diameter (DH) values, due to the formation of protein aggregates in solution...
March 2015: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/24839186/glossoscolex-paulistus-extracellular-hemoglobin-hbgp-oligomeric-dissociation-upon-interaction-with-sodium-dodecyl-sulfate-isothermal-titration-calorimetry-itc
#8
Fernanda Rosa Alves, Francisco Adriano O Carvalho, José Wilson P Carvalho, Marcel Tabak
Annelid erythrocruorins are respiratory proteins with high cooperativity and low autoxidation rates. The giant extracellular hemoglobin of the earthworm, Glossoscolex paulistus (HbGp), has a molecular mass of 3.6 MDa. In this work, isothermal titration calorimetry (ITC), together with DLS and fluorescence emission have been used to investigate the interaction of SDS with the HbGp in the oxy-form, at pH 7.0. Our ITC and DLS results show that addition of SDS induces oxy-HbGp oligomeric dissociation, while a small amount of protein aggregation is observed only by DLS...
October 2014: Biopolymers
https://www.readbyqxmd.com/read/24717174/cetyltrimethylammonium-chloride-ctac-effect-on-the-thermal-stability-of-oxy-hbgp-dynamic-light-scattering-dls-and-small-angle-x-ray-scattering-saxs-studies
#9
José Wilson P Carvalho, Francisco Adriano O Carvalho, Tatiana Batista, Patrícia S Santiago, Marcel Tabak
Glossoscolex paulistus (HbGp) hemoglobin is an oligomeric protein, displaying a quaternary structure constituted by 144 globin and 36 non-globin chains (named linkers) with a total molecular mass of 3.6MDa. CTAC effects on the oxy-HbGp thermal stability were investigated, by DLS and SAXS, at pH 5.0, 7.0 and 9.0. DLS data show that the oxy-HbGp-CTAC interactions induce a significant decrease of the protein thermal stability, with the formation of larger aggregates, at pH 5.0 and 7.0. In the acidic pH, oxy-HbGp 0...
June 1, 2014: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/24095792/characterization-of-rhinodrilus-alatus-hemoglobin-hbra-and-its-subunits-evidence-for-strong-interaction-with-cationic-surfactants-dtab-and-ctac
#10
Francisco A O Carvalho, José W P Carvalho, Ezer Biazin, Patrícia S Santiago, Marcel Tabak
Rhinodrilus alatus is an annelid and its giant extracellular hemoglobin (HbRa) has a molecular mass (MM) of 3500kDa. In the current study, the characterization of MM values of the HbRa subunits, and the effects of surfactants and alkaline pH upon HbRa stability were monitored. Electrophoresis, MALDI-TOF-MS and AUC show that the MM values of HbRa subunits are very close, but not identical to the Glossoscolex paulistus hemoglobin (HbGp). The monomer d is found to exist in, at least, two isoforms: the main one, d1, displays a MM of 16,166±16Da, and the second one, d2, is less intense with MM of 16,490±20Da...
January 2014: Comparative Biochemistry and Physiology. Part B, Biochemistry & Molecular Biology
https://www.readbyqxmd.com/read/23893030/sodium-dodecyl-sulfate-sds-effect-on-the-thermal-stability-of-oxy-hbgp-dynamic-light-scattering-dls-and-small-angle-x-ray-scattering-saxs-studies
#11
José Wilson P Carvalho, Fernanda Rosa Alves, Tatiana Batista, Francisco Adriano O Carvalho, Patrícia S Santiago, Marcel Tabak
Glossoscolex paulistus (HbGp) hemoglobin is an oligomeric protein, presenting a quaternary structure constituted by 144 globin and 36 non-globin chains (named linkers) with a total molecular mass of 3.6 MDa. SDS effects on the oxy-HbGp thermal stability were studied, by DLS and SAXS, at pH 5.0, 7.0 and 9.0. DLS and SAXS data show that the SDS-oxy-HbGp interactions induce a significant decrease of the protein thermal stability, with the formation of larger aggregates, at pH 5.0. At pH 7.0, oxy-HbGp undergoes complete oligomeric dissociation, with increase of temperature, in the presence of SDS...
November 1, 2013: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/23648596/ph-effect-upon-hbgp-oligomeric-stability-characterization-of-the-dissociated-species-by-auc-and-dls-studies
#12
Francisco Adriano O Carvalho, José Wilson P Carvalho, Fernanda Rosa Alves, Marcel Tabak
Glossoscolex paulistus (HbGp) extracellular hemoglobin is a giant oligomeric protein. It is constituted by 144 heme containing subunits and non-heme structures (linkers), with a total molecular mass of 3.6MDa. AUC and DLS studies were developed for three HbGp forms, oxy-, met- and cyanomet-, at several pH values, in order to characterize the species in solution upon oligomeric dissociation. Isolated SEC fractions, trimer and dodecamer, are less stable as compared to the whole oxy-HbGp. The monomer d displays a large thermal stability up to 59°C...
August 2013: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/23194839/thermal-denaturation-and-aggregation-of-hemoglobin-of-glossoscolex-paulistus-in-acid-and-neutral-media
#13
José Wilson P Carvalho, Francisco A O Carvalho, Patrícia S Santiago, Marcel Tabak
The thermal denaturation and aggregation of the HbGp, in the oxy- and cyanomet-forms, was investigated by DSC, AUC, DLS, optical absorption and CD, in the pH range from 5.0 to 7.0. Oxy-HbGp has a denaturation process partially reversible and dependent on the temperature. DSC melting curve is characterized by a single peak with T(c) value of 333.4 ± 0.2K for oxy-HbGp, while two peaks with T(c) values of 332.2 ± 0.1 and 338.4 ± 0.2K are observed for cyanomet-HbGp, at pH 7.0. In acidic pH oxy- and cyanomet-HbGp are more stable showing higher T(c) values and aggregation...
March 2013: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/23041455/urea-induced-unfolding-of-glossoscolex-paulistus-hemoglobin-in-oxy-and-cyanomet-forms-a-dissociation-model
#14
Francisco A O Carvalho, José Wilson P Carvalho, Patrícia S Santiago, Marcel Tabak
The urea effect on the giant extracellular hemoglobin of Glossoscolex paulistus (HbGp) stability was studied by analytical ultracentrifugation (AUC) and small angle X-ray scattering (SAXS). AUC data show that the sedimentation coefficient distributions curves c (S), at 1.0 mol/L of urea, display a single peak at 57 S, associated to the undissociated protein. The increase in urea concentration, up to 4.0 mol/L, induces the appearance of smaller species, due to oligomeric dissociation. The sedimentation coefficients and molecular masses are 9...
January 2013: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/22735266/conditional-expression-of-human-bone-gla-protein-in-osteoblasts-causes-skeletal-abnormality-in-mice
#15
Kazuhiro Ikeda, Tohru Tsukui, Daisuke Tanaka, Yojiro Maruyama, Kuniko Horie-Inoue, Satoshi Inoue
Bone Gla protein (BGP), also known as osteocalcin, is one of the most abundant γ-carboxylated noncollagenous protein in bone matrix and plays important roles in mineralization and calcium ion homeostasis. BGP is synthesized specifically in osteoblasts; however, its precise function in bone metabolism has not been fully elucidated. To investigate the in vivo function of human BGP (hBGP), we generated CAG-GFP(floxed)-hBGP transgenic mice carrying a transgene cassette composed of the promoter and a floxed GFP linked to hBGP cDNA...
July 20, 2012: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/22397813/on-the-temperature-stability-of-extracellular-hemoglobin-of-glossoscolex-paulistus-at-different-oxidation-states-saxs-and-dls-studies
#16
José Wilson P Carvalho, Patrícia S Santiago, Tatiana Batista, Carlos Ernesto Garrido Salmon, Leandro R S Barbosa, Rosangela Itri, Marcel Tabak
Glossoscolex paulistus hemoglobin (HbGp) was studied by dynamic light scattering (DLS) and small angle X-ray scattering (SAXS). DLS melting curves were measured for met-HbGp at different concentrations. SAXS temperature studies were performed for oxy-, cyanomet- and met-HbGp forms, at several pH values. At pH 5.0 and 6.0, the scattering curves are identical from 20 to 60 °C, and Rg is 108 Å, independent of the oxidation form. At pH 7.0, protein denaturation and aggregation occurs above 55 °C and 60 °C, for oxy and met-HbGp, respectively...
April 2012: Biophysical Chemistry
https://www.readbyqxmd.com/read/22286030/on-the-stability-of-the-extracellular-hemoglobin-of-glossoscolex-paulistus-in-two-iron-oxidation-states-in-the-presence-of-urea
#17
Francisco Adriano O Carvalho, Patrícia S Santiago, Marcel Tabak
The stability of the Glossoscolex paulistus hemoglobin (HbGp), in two iron oxidation states (and three forms), as monitored by optical absorption, fluorescence emission and circular dichroism (CD) spectroscopies, in the presence of the chaotropic agent urea, is studied. HbGp oligomeric dissociation, denaturation and iron oxidation are observed. CD data show that the cyanomet-HbGp is more stable than the oxy-form. Oxy- and cyanomet-HbGp show good fits on the basis of a two state model with critical urea concentrations at 220-222 nm of 5...
March 1, 2012: Archives of Biochemistry and Biophysics
https://www.readbyqxmd.com/read/21824807/autoxidation-of-giant-extracellular-hemoglobin-of-glossoscolex-paulistus-molecular-mechanism-and-oligomeric-implications
#18
Alessandra Lima Poli, Leonardo Marmo Moreira, Hidetake Imasato
Giant extracellular hemoglobins present high redox stability due to their supramolecular architecture, high number of polypeptide chains and great compaction of protein subunits. The oligomeric assembly and the changes in the polypeptidic structure can influence the autoxidation rate of the heme proteins, being that different nucleophiles can act in this process due to pH alterations. In the present work, we have studied the autoxidation rate of whole Glossoscolex paulistus (HbGp) giant extracellular hemoglobin, as well as the autoxidation rate of the isolated d monomer of HbGp studied regarding pH variations...
November 2011: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/21169685/crystallization-and-preliminary-structural-analysis-of-the-giant-haemoglobin-from-glossoscolex-paulistus-at-3-2-%C3%A3
#19
J F R Bachega, L Bleicher, E R Horjales, P S Santiago, R C Garratt, M Tabak
Glossoscolex paulistus is a free-living earthworm encountered in south-east Brazil. Its oxygen transport requirements are undertaken by a giant extracellular haemoglobin, or erythrocruorin (HbGp), which has an approximate molecular mass of 3.6 MDa and, by analogy with its homologue from Lumbricus terrestris (HbLt), is believed to be composed of a total of 180 polypeptide chains. In the present work the full 3.6 MDa particle in its cyanomet state was purified and crystallized using sodium citrate or PEG8000 as precipitant...
January 2011: Journal of Synchrotron Radiation
https://www.readbyqxmd.com/read/21074550/molecular-masses-and-sedimentation-coefficients-of-extracellular-hemoglobin-of-glossoscolex-paulistus-alkaline-oligomeric-dissociation
#20
Francisco Adriano O Carvalho, Patrícia S Santiago, Júlio C Borges, Marcel Tabak
The giant extracellular hemoglobin of Glossoscolex paulistus (HbGp) has a molecular mass (M) of 3600±100 kDa and a standard sedimentation coefficient (s20,w0) of 58 S, estimated by analytical ultracentrifugation (AUC). In the present work, further AUC studies were developed for HbGp, at pH 10.0, which favors oligomeric dissociation into lower M species. The HbGp oligomer is formed by globin chains a, b, c and d plus the linker chains. The pure monomeric fraction, subunit d, and HbGp at pH 10.0, in the presence of β-mercaptoethanol, were also studied...
January 1, 2011: International Journal of Biological Macromolecules
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