Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Of hemoglobin

Antosiewicz, J., Porschke, D. Electrostatics of hemoglobins from measurements of the electric dichroism and computer simulations. Biophys. J. 68 (1995) 655-664. [Pg.195]

Figure 2-1 S3. The ViewerLite shows an elaborate depiction of hemoglobin on the right-hand side, with the amino acids in a cascade window on the left. Figure 2-1 S3. The ViewerLite shows an elaborate depiction of hemoglobin on the right-hand side, with the amino acids in a cascade window on the left.
Positive-ion electrospray mass spectrum of human hemoglobin (a) as initially obtained with all the measured masses, and (b) after calculation of true mass, as in Figure 8.3. The spectrum transforms into two main peaks representing the main alpha and beta chains of hemoglobin with accurate masses as given. This transformation is fnlly automated. The letters A, B, C refer to the three chains of hemoglobin. Thus, A13 means the alpha chain with 13 protons added. [Pg.59]

Hemin is the complex between protoporphyrin and iron in the +3 oxidation state. Iron is in the +2 state in the heme of hemoglobin. The molecule has the following structure ... [Pg.443]

Other biomedical and biological appHcations of mictocapsules continue to be developed. For example, the encapsulation of enzymes continues to attract interest even though loss of enzyme activity due to harshness of the encapsulation protocols used has been a persistent problem (59). The use of mictocapsules in antibody hormone immunoassays has been reviewed (60). The encapsulation of hemoglobin as a ted blood substitute has received much attention because of AIDS and blood transfusions (61). [Pg.324]

Several pure hemoglobin solutions were later produced on a large scale for experimental use. A procedure was described for crystallization of hemoglobin and the product was evaluated in a series of animal trials (38—41). A 6 g/dL hemoglobin solution that had a P q of about 2.4—2.7 kPa (18—20... [Pg.161]

The transition between the T and R states of hemoglobin is also deeply involved in the Bohr effect and cooperativity. Therefore stabilization of either of the two stmctures should diminish these effects, which have important physiologic consequences. The clinical consequences of stabilization are not known. [Pg.162]

Fig. 2. Reaction of diphosphoglycerate (2,3-DPG) and deoxyhemoglobin. The molecule fits into the central cavity of hemoglobin and forms salt bridges with valine NA(I)p, histidines NA2(2)p, H2I(I43)p, and lysine EF6(82)p. A, E, and E correspond to specific hemoglobin hehces and NA is the sequence... Fig. 2. Reaction of diphosphoglycerate (2,3-DPG) and deoxyhemoglobin. The molecule fits into the central cavity of hemoglobin and forms salt bridges with valine NA(I)p, histidines NA2(2)p, H2I(I43)p, and lysine EF6(82)p. A, E, and E correspond to specific hemoglobin hehces and NA is the sequence...
AH of the reactions considered to be useful in the production of hemoglobin-based blood substitutes use chemical modification at one or more of the sites discussed above. Table 2 Hsts the different types of hemoglobin modifications with examples of the most common reactions for each. Differences in the reactions are determined by the dimensions and reactivity of the cross-linking reagents. Because the function of hemoglobin in binding and releasing... [Pg.162]

C rb myl tion. Modification of the amino-terminal groups of hemoglobin (Hb) by the carbamylation reaction using isocyanic acid [75-13-8]... [Pg.163]

Pyridoxal Derivatives. Various aldehydes of pyridoxal (Table 3) react with hemoglobin at sites that can be somewhat controlled by the state of oxygenation (36,59). It is thereby possible to achieve derivatives having a wide range of functional properties. The reaction, shown for PLP in Figure 3, involves first the formation of a Schiff s base between the amino groups of hemoglobin and the aldehyde(s) of the pyridoxal compound, followed by reduction of the Schiff s base with sodium borohydride, to yield a covalendy-linked pyridoxyl derivative in the form of a secondary amine. [Pg.163]

Fig. 3. (a) Reaction of pytidoxal 5 -phosphate (PLP) witii an amino-temiinal amino group of hemoglobin (Hb). The reagent is in the form of a Schiff s base with tris(hydroxymethyl)aminomethane [77-86-1] (Tris) buffet, and the reaction is a transamination, (b) The resulting unstable Schiff s base is reduced with... [Pg.163]

Optimization of the ATP—hemoglobin reaction conditions produced a preparation having a markedly reduced oxygen affinity. Five fractions from a reaction mixture, when isolated, were found to have P q values ranging from 1.1 to 5.0 kPa (8 to 38 torr), most withUtfle cooperativity (118). These results are consistent with those found with other polyfunctional reagents that react on the surface of hemoglobin. [Pg.166]

Purification. Hemoglobin is provided by the red blood ceU in highly purified form. However, the red ceU contains many enzymes and other proteins, and red ceU membranes contain many components that could potentially cause toxicity problems. Furthermore, plasma proteins and other components could cause toxic reactions in recipients of hemoglobin preparations. The chemical modification reactions discussed herein are not specific for hemoglobin and may modify other proteins as well. Indeed, multifimctional reagents could actually couple hemoglobin to nonhemoglobin proteins. [Pg.166]

Outdated Human Blood. If clinical efficacy and safety of hemoglobin solutions can be shown, the demand for product would soon outstrip the supply of outdated human blood. About 12 million units of blood (1 unit 480 mL) are used in the United States each year, and only about 500,000 outdate. The primary use of blood is in intraoperative and emergency settings. The quantity of blood available for use in production of blood substitutes depends on safety and efficient usage of blood products as well as on the demands on blood suppHes. [Pg.167]

J. M. Manning, ia E. Antonini, L. Rossi-Bemardi, and E. Chiancone, eds.. Methods in En mology, Hemoglobins, Academic Press, New York, 1981, pp. 159—167. Preparation of hemoglobin carbamylated at specific NH -terminal residues. [Pg.168]

CPR can be used to find continuous paths for complex transitions that might have hundreds of saddle points and need to be described by thousands of path points. Examples of such transitions include the quaternary transition between the R and T states of hemoglobin [57] and the reorganization of the retinoic acid receptor upon substrate entry [58]. Because CPR yields the exact saddle points as part of the path, it can also be used in conjunction with nonnal mode analysis to estimate the vibrational entropy of activation... [Pg.217]

The second example of an air pollutant that affects the total body burden is carbon monoxide (CO). In addihon to CO in ambient air, there are other sources for inhalation. People who smoke have an elevated CO body burden compared to nonsmokers. Individuals indoors may be exposed to elevated levels of CO from incomplete combustion in heating or cooking stoves. CO gas enters the human body by inhalation and is absorbed directly into the bloodstream the total body burden resides in the circulatory system. The human body also produces CO by breakdown of hemoglobin. Hemoglobin breakdown gives every individual a baseline level of CO in the circulatory system. As the result of these factors, the body burden can fluctuate over a time scale of hours. [Pg.102]

Sickle-cell anemia is the classic example of an inherited disease that is caused by a change in a protein s amino acid sequence. Linus Pauling proposed in 1949 that it was caused by a defect in the hemoglobin molecule he thus coined the term molecular disease. Seven years later Vernon Ingram showed that the disease was caused by a single mutation, a change in residue 6 of the P chain of hemoglobin from Glu to Val. [Pg.43]

Figure 3.13 The hemoglobin molecule is built up of four polypeptide chains two a chains and two (3 chains. Compare this with Figure 1.1 and note that for purposes of clarity parts of the a chains are not shown here. Each chain has a three-dimensional structure similar to that of myoglobin the globin fold. In sicklecell hemoglobin Glu 6 in the (3 chain is mutated to Val, thereby creating a hydrophobic patch on the surface of the molecule. The structure of hemoglobin was determined in 1968 to 2.8 A resolution in the laboratory of Max Perutz at the MRC Laboratory of Molecular Biology, Cambridge, UK. Figure 3.13 The hemoglobin molecule is built up of four polypeptide chains two a chains and two (3 chains. Compare this with Figure 1.1 and note that for purposes of clarity parts of the a chains are not shown here. Each chain has a three-dimensional structure similar to that of myoglobin the globin fold. In sicklecell hemoglobin Glu 6 in the (3 chain is mutated to Val, thereby creating a hydrophobic patch on the surface of the molecule. The structure of hemoglobin was determined in 1968 to 2.8 A resolution in the laboratory of Max Perutz at the MRC Laboratory of Molecular Biology, Cambridge, UK.

See other pages where Of hemoglobin is mentioned: [Pg.58]    [Pg.121]    [Pg.333]    [Pg.446]    [Pg.449]    [Pg.374]    [Pg.66]    [Pg.400]    [Pg.400]    [Pg.161]    [Pg.161]    [Pg.161]    [Pg.161]    [Pg.161]    [Pg.163]    [Pg.163]    [Pg.163]    [Pg.164]    [Pg.165]    [Pg.166]    [Pg.166]    [Pg.167]    [Pg.167]    [Pg.167]    [Pg.168]    [Pg.125]    [Pg.103]    [Pg.44]    [Pg.526]    [Pg.527]   
See also in sourсe #XX -- [ Pg.413 ]




SEARCH



A chain of human hemoglobin

Acid-Base Chemistry and Respiratory Function of Hemoglobin

Allosteric effectors of hemoglobin

Allosteric properties of hemoglobin

Autoxidation of hemoglobin

Binding of CO to Myoglobin, Hemoglobin, and Model Compounds

Binding of oxygen to myoglobin and hemoglobin

Biochemistry of Hemoglobin

Biosensors based on direct electron transfer of hemoglobin

Characterization of hemoglobin

Deoxygenation of hemoglobin

Derivatives of Hemoglobin

Direct electron transfer of hemoglobin

Direct electron transfer of protein hemoglobin

Electrophoresis of hemoglobin

Evolution of myoglobin/hemoglobin proteins

Functional Aspects of Hemoglobin

Globin chains, of hemoglobin

Hemoglobin and Effect of Transfusion

Hemoglobin of human

Herbicides of hemoglobin

Hereditary persistence of fetal hemoglobin

Hereditary persistence of fetal hemoglobin HPFH)

Inherited Disorders of Hemoglobin Structure and Synthesis

Low-spin compounds of hemoglobin

Of hemoglobin variants

Oxidation of hemoglobin

Oxygen affinity of hemoglobin

Oxygen dissociation curve of hemoglobin

Oxygenation of hemoglobin

P chains, of hemoglobin

Persistence of fetal hemoglobin

Phylogenetic Distribution of the Change in Hemoglobin Forms with Morphogenesis

Physiology, of myoglobin and hemoglobin

R state, of hemoglobin

Roles of hemoglobin and myoglobin

Salt bridges of hemoglobin

Spectrophotometric Determination of Hemoglobin

Structure and Functions of Fetal Hemoglobin

T state, of hemoglobin

Thalassemias, Lepore Hemoglobins, and Hereditary Persistence of Fetal Hemoglobin (HPFH)

The Standardized Determination of Hemoglobin

© 2024 chempedia.info