Hemoglobin human

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. 

Some Pathological Sequence Variants of Human Hemoglobin ... 

The primary structure of a protein is the sequence of residues in the peptide chain. Aspartame consists of phenylalanine (Phe) and aspartic acid (Asp), and so its primary structure is Phe-Asp. Three fragments of the primary structure of human hemoglobin are... 

FIGURE 19.20 One of the four polypeptide chains that make up the human hemoglobin molecule. The chains consist of alternating regions of a helix and p sheet. The a-helix regions are represented by red helices. The oxygen molecules that we inhale attach to the iron atom (blue sphere) and are curried through the bloodstream. 

NUMEROUS MUTANT HUMAN HEMOGLOBINS HAVE BEEN IDENTIFIED... 

Unzai S et al Rate constants for O2 and CO binding to the alpha and beta subunits within the R and T states of human hemoglobin. J Biol Chem 1998 273 23150. 

T gure l, Tyx)-dimensioml presentation of the o-chain of human hemoglobin. 9, residues in contact th the heme group residues that participate in the ctrpi contact , residues that participate in the ai pt contact (3). 

Itano, H. A. "Solubilities of Naturally Occurring Mixtures of Human Hemoglobin". Arch. Blochem. and Blophys., (1953),... 

Huisman, T. H. J. and Dozy, A. M., Studies on the heterogeneity of hemoglobin. IV. Chromatographic behavior of different human hemoglobins on anion-exchange cellulose (DEAE-cellulose), /. Chromatogr., 7, 180, 1962. 

Human hemoglobin (< + P) CaMVenhanced 35S promoter/ CaMV 35S terminator Transit peptide of small subunit of RubisCO of Pisum sativum N. tabacum 0.05% of seed protein 37... 

J. Thomas and G. N. LaMar, Heme orientational heterogeneity in deuterohemin-reconstituted horse and human hemoglobin characterized by proton NMR spectroscopy, Biochem, Biophys. Res. Commun. 119, 640-654 (1984). 

Foret et al.98 collected fractions of model proteins and variants of human hemoglobins after fractionation by CIEF, and then analyzed them by matrix-assisted laser desorption-time-of-flight-mass spectrometry (MALDI-TOF-MS). As the authors point out, MS is an orthogonal method to CIEF because it separates according to molecular mass. 

Table 9.2 Migration Time and Isoelectric Point Reproducibility for Human Hemoglobins A and S Analyzed by CIEF...

Nagai and Thergersen found that an alternative approach was required to achieve efficient expression of the -chain subunits of human hemoglobin in E. coli [55]. In this case, P-globin was produced as a fusion protein that possessed the sequence Ile-Glu-Gly-Arg between the 31 amino-terminal residues of X cll... 

Through the formation of polypeptide bonds between amino acids, very long chains of sequences are obtained. Generally, proteins consist of hundreds and thousands of amino acids. For example, human hemoglobin has four polypeptide chains, of which two are cf-chains and two are j3-chains. There are 141 amino acids in each a-chain with a sequence of... 

Guidotti, G., R. J. Hill, and IV. Konigsberg The structure of human hemoglobin. TI. The sepanition and amino acid composition of the tryptic peptides from the a and p chains. Journ. Biol. Chem. 237, 2184-2195 (1962). 

Konigsberg, W., and R. J. Hill The structure ol human hemoglobins. 111. The sequence of amino acid.s in the tryptic peptides of the a-chain. Journ. Biol. Chem. 237, 2517 -2561 (1962). 

From this type of analysis, one would conclude that t must be approximately 28 for a 10% reduction in protomer to cause a 95% reduction in the nucleus concentration. This is a rather startling apparent reaction order even assuming infinite cooperativity between protomers. It is recalled that Hofrichter et al. (1974) found from a similar analysis of the rate of nucleation of human hemoglobin S (HbS) at 30 C that the apparent reaction order for the nucleation of HbS aggregation was about 32. Of course, such analyses are not fully justifiable because one may not assume ideality in the solution properties of biopolymers at high concentrations, particularly at 200 mg/ml in the case of hemoglobin. The computation for the case of tubulin polymerization does, nonetheless, emphasize that nucleation would be an especially cooperative event if only tubulin, and not ring structures, played the active role in nuclei formation. 

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