We calculate the surface area buried in subunit interfaces of human deoxyhemoglobin and of horse methemoglobin. A larger surface area is buried in deoxy- than in methemoglobin as a result of tertiary and quaternary structure changes. In both molecules the dimer-dimer interface is closepacked. This implies that hydrophobicity stabilizes the deoxystructure, the free energy spent in keeping the su...

Experimental measurements of the diffusion coefficient of human methemoglobin were made at 25 degrees C with a modified Stokes diaphragm diffusion cell. A Millipore filter was used in place of the ordinary fritted disc to facilitate rapid achievement of steady state in the diaphragm. Methemoglobin concentrations varied from approximately 5 g/100 ml to 30 g/100 ml. The diffusion coefficient in t...

About 10 years ago we discovered that bubbling nitric oxide (NO) gas into KrebsRinger bicarbonate solution containing isolated precontracted strips of bovine coronary artery caused a rapid and pronounced, but transient, relaxant response that was antagonized by oxidized hemoproteins, such as methemoglobin, and by methylene blue. NO activated soluble guanylate cyclase prepared from coronary arte...

About 10 years ago we discovered that bubbling nitric oxide (NO) gas into KrebsRinger bicarbonate solution containing isolated precontracted strips of bovine coronary artery caused a rapid and pronounced, but transient, relaxant response that was antagonized by oxidized hemoproteins, such as methemoglobin, and by methylene blue. NO activated soluble guanylate cyclase prepared from coronary arte...

Methemoglobin is a type of hemoglobin in which the ferrous ion has been oxidized to the ferric state. It is therefore incapable of combining with or transporting the oxygen molecule, which is replaced by a hydroxyl radical. Methemoglobinemia can be acquired or inherited. Most cases are acquired and are primarily due to exposure to certain drugs and chemicals, such as nitrates, nitrites, quinone...

To the Editor: A recent letter in this journal described methemoglobinemia and hemolysis due to rasburicase in a patient with glucose-6-phosphate dehydrogenase (G6PD) deficiency [1]. We would like to report on the management of a patient with rasburicase induced methemoglobinemia and G6PD deficiency. DS is a 12-year-old Laotian male who presented with a white blood cell count of 533,900/mm (89%...

Erythrocytes from heterozygous carriers of the high oxygen affinity mutant hemoglobin, Hb Wood, demonstrate lower rates of methemoglobin reduction than normal human red cells when incubated in the in vitro system of Beutler and Baluda. The rate of methemoglobin reduction in red cells from an individual who is heterozygous for both NADH-methoglobin reductase deficiency and Hb Wood shows the comb...

Oxidation of oxyhemoglobin by nitrite is characterized by the presence of a lag phase followed by the autocatalysis. In phosphate buffer, an asymmetric ESR signal is detected at g = 2.005 (hereafter referred to as the g = 2 radical) during the oxidation which is similar to that of the methemoglobin free radical generated from methemoglobin and H2O2. Catalase and KCN prolong the oxidation, indic...

Lasers are widely used in dermatology to remove telangiectasias. Increasing the efficiency of sclerosis deep-lying and large telangiectasias with laser radiation is possible by changing optical transmission skin when it heated converting hemoglobin blood contained into methemoglobin. The influence concentration methemoglobin on absorption light human poorly understood, which determines relevanc...