Hemoglobins quantitation

We can determine quantitatively the physiological significance of the sigmoid nature of the hemoglobin oxygen-binding curve, or, in other words, the biological importance of cooperativity. The equation... 

Heme (C34H3204N4Fe) represents an iron-porphyrin complex that has a protoporphyrin nucleus. Many important proteins contain heme as a prosthetic group. Hemoglobin is the quantitatively most important hemoprotein. Others are cytochromes (present in the mitochondria and the endoplasmic reticulum), catalase and peroxidase (that react with hydrogen peroxide), soluble guanylyl cyclase (that converts guanosine triphosphate, GTP, to the signaling molecule 3, 5 -cyclic GMP) and NO synthases. 

Manning JM et aJ Normal and abnormal protein subunit interactions in hemoglobins.] Biol Chem 1998 273 19359-Mario N, Baudin B, Giboudeau J Qualitative and quantitative analysis of hemoglobin variants by capillary isoelectric focusing. J Chromatogr B Biomed Sci Appl 1998 706 123-Reed W, Vichinsky EP New considerations in the treatment of sickle cell disease. Annu Rev Med 1998 49 46l. 

Mlcrochromatographlc Methods During the past two years rapid. Inexpensive, miniaturized column chromatographic methods for the separation of hemoglobins have been developed These methods are designed for the qualitative detection and quantitative determination of hemoglobins In normal and abnormal conditions and cover the quantitation of Hb-A2 the detection of Hb-S, Hb-C other abnormal Hbs differentiation of various conditions In adults and the detection of hemoglobinopathies especially sickle cell anemia at birth (27, 28, 29, 30) ... 

The Determination of Fetal Hemoglobin (Hb-F). Specific properties of Hb-F have given rise to various methods for Its detection and quantitation which are based on electrophoretic and chromatographic mobilities of Hb-F, on Its slow rate of... 

Hb-F can also be separated from Hb-A and many of Its variants by both onion- and caiion-chnomatogAjophy. However, In most Instances Hb-F elutes together with the minor adult hemoglobin Hb-Ai thus preventing Its accurate quantitation. 

Y. Nomura and M. Tamura. Quantitative analysis of hemoglobin oxygenation state of rat brain in vivo by picosecond time-resolved spectrophotometry. Journal of Biochemistry, 109 455-461, 1991. 

Contamination with endotoxin is an important and frustrating problem in LEH manufacturing for two reasons. Firstly, hemoglobin has a strong tendency to bind endotoxin, where one hemoglobin molecule binds to four endotoxin molecules (K 3.1 x lO M) (117). Secondly, endotoxin has amphiphilicity that enables its stable insertion into lipid bilayer. Such an interaction not only presents contamination and stability problems, but also hampers accurate quantitation of endotoxin. The best possible way to prevent endotoxin contamination is to use aseptic precautions with utmost care. All the machinery, filters, and water should be endotoxin-free. Glass and metallic components may be dry-heat sterilized at about 200° C for three... 

Iron (Fe) is quantitatively the most important trace element (see p. 362). The human body contains 4-5 g iron, which is almost exclusively present in protein-bound form. Approximately three-quarters of the total amount is found in heme proteins (see pp. 106,192), mainly hemoglobin and myoglobin. About 1% of the iron is bound in iron-sulfur clusters (see p. 106), which function as cofactors in the respiratory chain, in photosynthesis, and in other redox chains. The remainder consists of iron in transport and storage proteins (transferrin, ferritin see B). 

The last column in the table lists some of the functions of minerals. It should be noted that almost all of the macroelements in the body function either as nutrients or electrolytes. Iodine (as a result of its incorporation into iodothyronines) and calcium act as signaling substances. Most trace elements are cofactors for proteins, especially for enzymes. Particularly important in quantitative terms are the iron proteins hemoglobin, myoglobin, and the cytochromes (see p. 286), as well as more than 300 different zinc proteins. 

Biroccio A, Urbani A, Massoud R, di Ilio C, Sacchetta P, Bernardini S, Cortese C, Federici G (2005) A quantitative method for the analysis of glycated and glutathionylated hemoglobin by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Anal Biochem Jan 336 279-288... 

Hemolysis is the leakage of hemoglobin into liquid such as plasma, and is due to disruption of the erythrocytes. Within the body, hemolysis maybe caused by some diseases or poisons, whereas hemolysis outside the body, as in artificial organs, is caused by physical or chemical factors. If erythrocytes are placed in water, hemolysis will occur as the cells rupture due to the difference in osmotic pressure between water and the intracellular liquid. Hemolysis in artificial organs and their accessories occurs due to a variety of physical factors, including turbulence, shear, and changes of pressure and velocity. It is difficult, however, to obtain any quantitative correlation between the rates of hemolysis and such physical factors. 

However, quantitative environmental exposure data for humans or other animals are often sadly lacking because studies are usually retrospective, and so, samples of body fluids will not have been taken. Bio markers of exposure are relatively transient and even conjugate with hemoglobin in blood, which are the most persistent, and are generally only detectable for... 

AFFINITY. The tendency of an atom or compound to react or combine with atoms or compounds of different chemical constitution. For example, paraffin hydrocarbons were so named because they are quite unreactive, the word paraffin meaning very little affinity." The hemoglobin molecule has a much greater affinity for carbon monoxide Ilian for oxygen. The free energy decrease is a quantitative measure of chemical affinity. 

More recently, a new test (.HemoQuant) has been developed. This test involves the chemical conversion of stool heme to porphyrins that can be assayed fluorometrically. The Lest also detects porphyrins present in stool as a result of bacterial and enzymatic degradation of hemoglobin as it travels through the intestines. Thus, this new test provides a quantitative measure of all blood that enters the gastrointestinal tract. It appears to be biochemically sound and is considered a methodological breakthrough. 

Recently Horbettl02) and Brash and ten Hove 103) have quantitatively demonstrated the Vroman effect in a series of experiments studying competitive adsorption of fibrinogen, albumin, IgG, and hemoglobin from diluted plasma. 

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