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Kinetic and mechanistic studies of the peroxynitrite-mediated oxidation of oxymyoglobin and oxyhemoglobin

CHEMICAL RESEARCH IN TOXICOLOGY 2000年第4期13卷 287-293页

作者： Exner, M Herold, S ETH Zentrum Anorgan Chem Lab CH-8092 Zurich Switzerland

Kinetic studies of the peroxynitrite-mediated oxidations of oxymyoglobin (MbFeO(2)) and oxyhemoglobin (HbFeO(2)) showed that the mechanisms of these reactions are more complex than what had previously been reported;both reactions proceed in two steps. For myoglobin, we found that the small amount of deoxymyoglobin (MbFe(II)) which is in equilibrium with MbFeO(2) is first oxidized by peroxynitrous acid to ferryl myoglobin (MbFe(IV)=O). Then, in the second step, MbFe(IV)=O is reduced by peroxynitrous acid to metmyoglobin (metMb). The second-order rate constant values obtained at pH 7.3 and 20 degrees C for the two steps are (5.4 +/- 0.2) x 10(4) and (2.2 +/- 0.1) x 10(4) M-1 s(-1), respectively. Analogous studies with hemoglobin suggest that its reaction with peroxynitrite follows the same mechanism. In this case, the second-order rate constant values measured at pH 7.0 and 20 degrees C for the two steps are (8.8 +/- 0.4) x 10(4) and (9.4 +/- 0.7) x 10(4) M-1 s(-1), respectively. A possible mechanism in the absence as well as in the presence of CO2 and the relevance of these reactions in vivo are discussed.

关键词：二氧化碳/代谢氢离子浓度肌红蛋白/代谢硝酸盐类/药理学氧化还原氧合血红蛋白/代谢

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Photohemolysis sensitized by the furocoumarin imperatorin and its oxyfunctionalized derivatives

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PHOTOCHEMISTRY AND PHOTOBIOLOGY 1999年第4期69卷 410-420页

作者： Potapenko, AY Kyagova, AA Andina, ES Zhuravel, NN Lysenko, EP Möller, M Stopper, H Adam, W Saha-Möller, CR Russian State Med Univ Dept Med & Biol Phys Moscow 117869 Russia Univ Wurzburg Inst Pharmacol & Toxicol Wurzburg Germany Univ Wurzburg Inst Organ Chem D-8700 Wurzburg Germany

The dark and photosensitized (366 mm) hemolytic effects of imperatorin and its photooxidation products, the hydroperoxides I and II as well as the corresponding alcohol of the hydroperoxide I (imperatorin alcohol), were studied on human erythrocytes, Imperatorin was shown to photosensitize hemolysis, its fluence (D) dependence of the rate of photohemolysis (V) followed the equation V = V-0 + aD(2) + bD(1/2), in which V-0 is the dark hemolysis rate and a and b are constants. At fluences below 200 kJ/m(2), the main hemolytic contribution derives from the bD(1/2) component, which is due to the in situ formation of the imperatorin hydroperoxides, while at fluences higher than 200 kJ/m(2), the main contribution corresponds to the aD(2) component due to the two-photon damage of cell membranes. Hydroperoxides I and II induce oxyhemoglobin cross-linking, as well as its conversion to methemoglobin and hemichrome. These reactions involve hydroxyl and alkoxy radicals, as the hemolysis and oxyhemoglobin conversion could be inhibited by t-butanol and butylated hydrotoluene. For comparison, the dark hemolytic effect of the imperatorin alcohol was approximately 10-fold less than of the hydroperoxides.

关键词：黑暗红细胞/药物作用红细胞/代谢红细胞/辐射效应溶血/药物作用溶血/辐射效应氧化还原氧合血红蛋白/药物作用氧合血红蛋白/代谢光生物学补骨脂素类/化学补骨脂素类/药理学人类

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EFFECT OF SODIUM PARA-AMINOSALICYLATE ON OXYGEN-AFFINITY IN NORMAL, SICKLE AND FETAL HUMAN-BLOOD

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JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS 1976年第2期199卷 441-453页

作者： LAASBERG, LH HEDLEYWHYTE, J LAVER, MB HARVARD UNIV SCH MED DEPT ANAESTHESIA BOSTON MA 02115 USA

Sodium p-aminosalicylate (sodium salt of 2-hydroxy-4-aminobenzoic acid, Na-PAS) lowers the O2 affinity of normal adult human, placental, heterozygous and homozygous sickle cell anemic whole blood at ***. C. The reduction of O2 affinity is related to the type of Hb in the blood. The mean P50 .+-. SE at pH 7.40 for normal, placental, heterozygous and homozygous sickle cell anemic blood is 26.2 .+-. 0.1, 20.8 .+-. 0.3, 26.8 .+-. 0.3 and 31.0 .+-. 0.5 mm Hg;in the presence of 5.7 mmol of Na-PAS/l of blood the P50 values are increased to 28.0 .+-. 0.3, 22.9 .+-. 0.8, 30.5 .+-. 0.6 and 33.9 .+-. 0.3 mm Hg, respectively. The Bohr effect in normal and placental blood at this Na-PAS concentration is essentially unchanged: in heterozygous and homozygous sickle cell anemic blood, the Bohr factor (.DELTA. log P50/.DELTA. pH) is reduced from -0.48 .+-. 0.02 to -0.41 .+-. 0.01 and from -0.53 .+-. 0.03 to -0.48 .+-. 0.01. The Hill constants (n) of normal and placental blood are not affected by Na-PAS. In homozygous and heterozygous sickle blood, high concentrations of Na-PAS (22.9 mmol/l) decrease the Hill constant from 2.55 to 2.35 and from 2.56 to 2.28, respectively. Na-PAS is more firmly bound to red blood cells than to plasma. The binding of Na-PAS is probably primarily ionic in nature since the drug can be almost completely removed from blood components by dialysis. The changes in O2 affinity caused by Na-PAS are consistent with conformational changes (R .fwdarw. T) which enhance the presence of deoxyHb.

关键词：氨基水杨酸类/药理学贫血镰状细胞性/血液透析二磷酸甘油酸类/血液红细胞/代谢红细胞异常/代谢胎血/药物作用血红蛋白测定杂合子纯合子氢离子浓度氧/血液氧合血红蛋白/代谢胎盘血浆/代谢镰状细胞遗传性状/血液 p-氨基水杨酸/血液 p-氨基水杨酸/药理学成年人女(雌)性人类妊娠

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The oxygen trail: tissue oxygenation

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BRITISH MEDICAL BULLETIN 1999年第1期55卷 96-108页

作者： Nathan, AT Singer, M UCL Med Sch Bloomsbury Inst Intens Care Med Rayne Inst London WC1E 6JJ England

Aerobic cellular respiration depends on the efficient supply of oxygen and substrate to the mitochondria. There is an oxygen cascade from the environment to the subcellular environment. Efficient oxygen delivery depends on the coordinated interaction between the respiratory and circulatory systems. The circulation at both macro- and microvascular levels is under the control of humoral and neural factors. There is local autoregulation of flow at the tissue level by metabolic factors which reflect the energy state of the tissues. The response to hypoxia involves the activation of cytokines and genetically controlled factors which maximise capillary perfusion and haemoglobin concentration, and regulate cell metabolism. The formation of reactive oxygen species under such conditions has a detrimental effect on the mitochondria with respiratory chain dysfunction, increased permeability transition, and cell death. This review aims to explore the mechanisms by which the body attempts to maintain tissue oxygen levels at conditions optimal for cell survival.

关键词：线粒体/代谢氧耗量/生理学氧合血红蛋白/代谢肺换气/生理学活性氧/生理学再灌注损伤/代谢信号传导/生理学人类

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Metal complexes as allosteric effectors of human hemoglobin:: An NMR study of the interaction of the gadolinium(III) bis(m-boroxyphenylamide)diethylenetriaminepentaacetic acid complex with human oxygenated and deoxygenated hemoglobin

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BIOPHYSICAL JOURNAL 1999年第5期76卷 2735-2743页

作者： Aime, S Digilio, G Fasano, M Paoletti, S Arnelli, A Ascenzi, P Univ Turin Dipartimento Chim IFM I-10125 Turin Italy Osped Civile USL 61 I-12038 Savigliano Italy Terza Univ Roma Dipartimento Biol I-00154 Rome Italy

The boronic functionalities on the outer surface of the Gd(III) bis(m-boroxyphenylamide)DTPA complex (Gd(III)L) enable it to bind to fructosamine residues of oxygenated glycated human adult hemoglobin. The formation of the macromolecular adduct can be assessed by NMR spectroscopy via observation of the enhancement of the solvent water proton relaxation rate. Unexpectedly, a strong binding interaction was also observed for the oxygenated unglycated human adult hemoglobin, eventually displaying a much higher relaxation enhancement. From relaxation rate measurements it was found that two Gd(III)L complexes interact with one hemoglobin tetramer (K-D = 1.0 x 10(-5) M and 4.6 x 10(-4) M, respectively), whereas no interaction has been observed with monomeric hemoproteins. A markedly higher affinity of the Gd(III)L complex has been observed for oxygenated and aquo-met human adult hemoglobin derivatives with respect to the corresponding deoxy derivative. Upon binding, a net change in the quaternary structure of hemoglobin has been assessed by monitoring the changes in the high-resolution H-1-NMR spectrum of the protein as well as in the Soret absorption band. On the basis of these observations and the B-11 NMR results obtained with the diamagnetic La(III)L complex, we suggest that the interaction between the lanthanide complex and deoxygenated, oxygenated, and aquo-met derivatives of human adult hemoglobin takes place at the 2,3-diphosphoglycerate (DPG) binding site, through the formation of N-->B coordinative bonds at His(143 beta) and His(2 beta) residues of different beta-chains. The stronger binding to the oxygenated form is then responsible for a shift of the allosteric equilibrium toward the high-affinity R-state. Accordingly, Gd(III)L affinity for oxygenated human fetal hemoglobin (tacking His(143 beta)) is significantly lower than that observed for the unglycated human adult tetramer.

关键词：别构部位生物物理学胎儿血红蛋白/化学胎儿血红蛋白/代谢钆DTPA/代谢血红蛋白A/化学血红蛋白A/代谢血红蛋白类/化学血红蛋白类/代谢动力学磁共振波谱学模型化学氧合血红蛋白/化学氧合血红蛋白/代谢蛋白质结合蛋白质构象成年人人类

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Effects of selenium dioxide on blood and femoral bone marrow of rats

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JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH-PART A-CURRENT ISSUES 2000年第7期59卷 553-560页

作者： Chen, CY Lin, TH Kaohsiung Med Coll Sch Technol Med Sci Kaohsiung 80708 Taiwan Foo Yin Inst Technol Dept Med Technol Kaohsiung Taiwan

This study was undertaken to investigate the effects of selenium dioxide (SeO2) on rat blood and femoral bone-marrow oxidant mechanisms. Treatment with SeO2, 67 mu g Se/kg ip daily for 14 d, significantly decreased lipid peroxidation and the concentrations of Fe in serum and bone marrow. The concentrations of Se in serum and bone-marrow cells were significantly increased after SeO2 treatment. The activities of glutathione peroxidase (GPx) in blood and bone-marrow cells were markedly increased. The levels of oxyhemoglobin in blood were significantly increased, while the concentrations of methemoglobin were decreased after SeO2 administration. The fragility of erythrocytes membranes was significantly decreased in SeO2-treated rats compared to controls. Data suggest that treatment with a low dose of SeO2 may provide antioxidant nutrients to blood and bone marrow.

关键词：骨髓/药物作用骨髓/代谢骨髓细胞/药物作用骨髓细胞/代谢细胞存活/药物作用红细胞衰老/药物作用股骨/药物作用股骨/代谢谷胱甘肽过氧化酶/血液谷胱甘肽过氧化酶/代谢注射腹腔内铁/血液铁/代谢脂质过氧化作用/药物作用高铁血红蛋白/代谢氧化剂/血液氧化剂/代谢氧合血红蛋白/代谢大鼠 Sprague-Dawley 硒/血液硒/代谢硒化合物/血液硒化合物/药理学动物男(雄)性大鼠

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Ascorbate induced cross-linking of oxyhemoglobin subunits

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Indian Journal of Experimental Biology 2000年第3期38卷 280-282页

作者： Sur, Arghya Pal, Keya Sen, Suvajit Chakrabarti, Sasanka DepartmentofBiochemistry UniversityCollegeofMedicineCalcuttaIndia.

Ascorbic acid during oxidation in vitro can generate H2O2 which induces non-disulphide covalent cross-linking of co-incubated oxyhemoglobin. The cross-linking phenomenon mediated by H2O2 takes place possibly without the involvement of hydroxyl radicals as evident from the failure of radical scavengers like mannitol and dimethyl sulphoxide as well as metal-chelator, to inhibit the process. This pro-oxidant effect of ascorbic acid may have physiological significance in red blood cells in vivo.

关键词：抗坏血酸/药理学过氧化氢酶/药理学交联试剂过氧化氢/代谢氧化还原氧合血红蛋白/化学氧合血红蛋白/药物作用氧合血红蛋白/代谢超氧化物歧化酶/药理学人类

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The oxyhemoglobin reaction of nitric oxide

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PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 1999年第16期96卷 9027-9032页

作者： Gow, AJ Luchsinger, BP Pawloski, JR Singel, DJ Stamler, JS Duke Univ Med Ctr Howard Hughes Med Inst Durham NC 27710 USA Duke Univ Med Ctr Dept Med Durham NC 27710 USA Montana State Univ Dept Chem & Biochem Bozeman MT 59717 USA Duke Univ Dept Cell Biol Durham NC 27710 USA

The oxidation of nitric oxide (NO) to nitrate by oxyhemoglobin is a fundamental reaction that shapes our understanding of NO biology. This reaction is considered to be the major pathway for NO elimination from the body;it is the basis for a prevalent NO assay;it is a critical feature in the modeling of NO diffusion in the circulatory system;and it informs a variety of therapeutic applications, including NO-inhalation therapy and blood substitute design. Here we show that, under physiological conditions, this reaction is of little significance. Instead, NO preferentially binds to the minor population of the hemoglobin's vacant hemes in a cooperative manner, nitrosylates hemoglobin thiols, or reacts with liberated superoxide in solution. In the red blood cell, superoxide dismutase eliminates superoxide, increasing the yield of S-nitrosohemoglobin and nitrosylated hemes, Hemoglobin thus serves to regulate the chemistry of NO and maintain it in a bioactive state. These results represent a reversal of the conventional view of hemoglobin in NO biology and motivate a reconsideration of fundamental issues in NO biochemistry and therapy.

关键词：电子自旋共振谱学红细胞/生理学动力学模型化学一氧化氮/化学一氧化氮/代谢氧合血红蛋白/化学氧合血红蛋白/代谢分光光度法超氧化物类/血液人类

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KINETICS OF OXYGEN AND CARBON-MONOXIDE BINDING TO SYNTHETIC ANALOGS OF MYOGLOBIN AND HEMOGLOBIN ACTIVE-SITES

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PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 1975年第3期72卷 1166-1170页

作者： CHANG, CK TRAYLOR, TG UNIV CALIF SAN DIEGODEPT CHEMLA JOLLACA 92037

Kinetics of reversible oxygenation and carbon monoxide complex formation of the simple heme compounds pyrroheme-N-[3-(1-imidazolyl)propyl]amide and pyrroheme-3-(3-pyridyl)propyl ester have been measured in different solvent environments. The oxygen on and off rates and equilibria of these compounds can be made to closely match those of myoglobin, of hemoglobin alpha chains, or of the various steps for hemoglobin by varying solvent environment or the basicity of the proximal base. These results suggest that the protein could alter oxygen on rates by varying the basicity of the proximal base and the off rates by changing the polarity of the distal environment.

关键词：结合部位一氧化碳/代谢碳氧血红蛋白/代谢血红素/代谢血红蛋白类/代谢动力学肌红蛋白/代谢氧/代谢氧合血红蛋白/代谢

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DIMETHYL ADIPIMIDATE - NEW ANTISICKLING AGENT

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PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 1975年第1期72卷 43-46页

作者： LUBIN, BH PENA, V MENTZER, WC BYMUN, E BRADLEY, TB PACKER, L CHILDRENS HOSP MED CTRBRUCE LYON MEM RES LABOAKLANDCA 94609 SAN FRANCISCO GEN HOSP SAN FRANCISCOCA 94110 UNIV CALIF LAWRENCE BERKELEY LABENVIRONM DIVBERKELEYCA 94720 VET ADM HOSP SAN FRANCISCOCA 94121 UNIV CALIF DEPT PHYSIOL ANATBERKELEYCA 94720

A new approach to the prevention of sickling in vitro by use of the bifunctional crosslinking reagent, dimethyl adipimidate, is described. Prior treatment of sickle erythrocytes with dimethyl adipimidate will inhibit sickling in completely deoxygenated erythrocytes. Treated erythrocytes do not demonstrate the potassium loss and viscosity increase that usually accompany sickling. The oxygen affinity of hemoglobin in these cells is increased independently from changes in the concentration of 2,3-diphosphoglycerate. The hemoglobin obtained from treated erythrocytes contains a high-molecular-weight component as well as additional positively charged components. The relative degree to which chemical modification and/or crosslinking is an essential part of the antisickling properties of the material is not known.

关键词：贫血镰状细胞性/血液血液黏度色谱法凝胶二磷酸甘油酸类/代谢剂量效应关系药物红细胞异常/药物作用红细胞异常/代谢血红蛋白镰状/代谢酰亚胺类/药理学氧/血液氧合血红蛋白/代谢钾/代谢人类

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