Rabbit hemoglobin biosynthesis: use of human hemoglobin chains to study molecule completion

A cell-free protein-synthesizing system made from rabbit reticulocytes was used to incorporate (14)C-amino acids into hemoglobin. Electrophoretic analyses of the soluble products of this cell-free system revealed a fraction containing rabbit (14)C-alpha chains in addition to the rabbit (14)C-hemoglobin. The addition of isolated human hemoglobin beta chains to this system during active synthesis inhibited the release of newly synthesized rabbit (14)C-beta chains into solution from the ribosome fraction. This inhibition was possibly a result of hybrid hemoglobin formation between rabbit alpha and human beta chains. A model of hemoglobin construction in which soluble alpha chains are intermediates is suggested. These alpha chains may aid in the release of beta chains from the polyribosomes during the completion of the hemoglobin molecule.     

Gelation of sickle cell hemoglobin: effects of hybrid tetramer formation in hemoglobin mixtures

The altered gelation behavior found in mixtures of sickle cell hemoglobin with other hemoglobins is due to the formation of hybrid hemoglobin tetramers from unlike dimers. The hemoglobins need not possess the deoxy quaternary structure for gelation to occur; liganded forms are also capable of participation in gelation.     

Oxygenation properties of snake hemoglobin

Natrix taxispilota hemoglobin has a very high oxygen affinity which depends upon pH in an unusual manner. The oxygen affinity increases slightly upon protein dilution, but the pK's of the Bohr groups are unchanged. Oxidation promotes hemoglobin polymerization, which can be inhibited by prior treatment with iodoacetamide. Reaction with iodoacetamide also causes a slight increase in the oxygen affinity, no change in the pK's of the Bohr groups, and a drastic reduction in heme-heme interaction.     

Electrophoresis of hemoglobin in single erythrocytes

A technique for electrophoretic analysis of the hemoglobin mixtures from single erythrocytes has been developed. Hemoglobin mixtures were separated into their constituents, A(2), A, C, S, and J, at least qualitatively.     

Transport of oxygen through hemoglobin solutions

An expression is derived for the steady-state diffusion rate of oxygen through a solution or suspension of oxygen-carrying particles. Several special cases of interest are discussed and compared with the data of Hemmingsen and Scholander. Their observed dependence of the rate of specific oxygen transport on pressure and pH is consistent with the present expression.     

Transport of gases through hemoglobin solution

A mathematical theory is developed to explain the observed enhancement of oxygen transport through solutions by hemoglobin. At high partial pressures of oxygen, ordinary diffusion through the solvent accounts for all transport of oxygen, but at low partial pressures the transport may be increased many fold by the presence of hemoglobin. This phenomenon is explained and the possible role of this phenomenon in living organisms is discussed. The theory also indicates a new method of determining dissociation curves from diffusion experiments.     

超声波破胞条件对猪血血红素提取效果的影响

为了有效利用猪血资源,减少猪血的环境污染,采用超声波酶解法水解血红蛋白制备血红素,研究了超声波破胞技术对血红素提取效果的影响。以血红素提取率为考察指标,通过单因素试验和正交试验确定了最佳工艺条件即:血红素与水的体积比1∶7,超声功率300W,超声次数60次,间歇比2∶5,破胞后经过酶水解,得到血红素。在此工艺条件下测得血红素提取率为652.71μg/mL。     

The Hill plot and the energy of interaction in hemoglobin

The Hill plot does not independently yield the average free energy of interaction per binding site, as has been proposed by Wyman, but rather the difference between the free energies of interaction on binding the first and last ligands. It is shown that additional data (or assumptions) and a model for cooperative behavior are required to obtain the average free energy of interaction.     

Fetal hemoglobin variants in mice

Two strains of mice, DBA and C3H, have a fetal globin polypeptide chain which differs in electrophoretic mobility from the corresponding fetal chain of the C57B1 strain. Mice of the DBA and C3H strains also differ from those of the C57B1 in adult hemoglobin type. Results of backcrossing the (DBA x C57B1) hybrid to the C57B1 suggest that the fetal chain locus and the adult beta-chain locus are closely linked.     

Conformational equilibria in spin-labeled hemoglobin

A component characteristic of deoxyhemoglobin appears in the paramagnetic resonance spectrum of spin-labeled oxyhemoglobin, and vice versa, under conditions of pH and ionic strength consistent with the interpretation that the spectrum is sensitive to the conformational equilibrium of the carboxy-terminal histidines. The oxygenation-induced change in the resonance spectrum is discussed in terms of shifts in this equilibrium.