Globin types

Burmester. T, Ebner, B., Weich, B., and Hankeln.T. 2002. Cytoglobin A novel globin type ubiquitously expressed in vertebrate tissues Mol. Biol. Evol. 19 416 421. 

Superoxide is formed (reaction 1) in the red blood cell by the auto-oxidation of hemoglobin to methemo-globin (approximately 3% of hemoglobin in human red blood cells has been calculated to auto-oxidize per day) in other tissues, it is formed by the action of enzymes such as cytochrome P450 reductase and xanthine oxidase. When stimulated by contact with bacteria, neutrophils exhibit a respiratory burst (see below) and produce superoxide in a reaction catalyzed by NADPH oxidase (reaction 2). Superoxide spontaneously dismu-tates to form H2O2 and O2 however, the rate of this same reaction is speeded up tremendously by the action of the enzyme superoxide dismutase (reaction 3). Hydrogen peroxide is subject to a number of fates. The enzyme catalase, present in many types of cells, converts... 

The saturated HpHb complex of type 1-1 was formed in solution and mixed with a pure solution of globin. The proteins were then separated by starch gel electrophoresis with a neutral phosphate buffer. The procedure was afterward repeated, but with a solution of Hp-globin complex mixed with an Hb solution. 

Considerable synergism was found in the action of the two types of agents, both in vitro and in vivo. Figure 2.5 shows the dramatic increase of epirabicin efficacy in mice breast carcinoma in the presence of p-globin derived heptapeptide, the so called W-hemorphin-5. The data accumulated allow to consider endogenous antiproliferative peptides or their synthetic derivatives as pronusing second line pharmaceuticals for combined application with other drags in cancer therapy. 

In view of the high affinity of arsenic for thiol functions, it can be expected that lewisite and CVAA will bind to cysteine residues of proteins. When human blood was incubated with 20 nM to 0.2 mM of [14C]lewisite, 25-50% of the dose became associated with globin (35). Electrospray tandem MS provided evidence for the presence of a CVAA-crosslink between the cysteine-93 and cysteine-112 residues in fi-globin. Whether this was the only type of adduct has not yet been completely elucidated. It must be remarked, however, that this result was in contrast with results obtained by others for the analogous phenyldichloroarsine, for which binding to human hemoglobin could not be observed. 

What types of mutations are found within the hemoglobin /3-globin gene cluster ... 

Investigations of static structures include architectural descriptions, comparisons and classifications, and identifications of recurrent patterns such as supersecondary structures. Examples include the classification of types of proteins by Levitt and Chothia (28), the hierarchical analysis of protein structures by Rose (29), or the comparison of globin structures by Lesk and Chothia (30). 

Table 53 gives a list of a number of cobalt(III)-superoxo complexes which have been isolated as crystalline solids. There is a marked preponderance of complexes of the type [Co(SB)(B)(02)] (SB = SchifF base). The base adducts of simple Co11 porphyrins have low affinities for dioxygen at room temperature and consequently their 1 1 adducts with 02 are not isolable. In contrast, exposure of a solid sample of Collman s picket fence porphyrin system [Co(TpivPP)(iV-Meim)] to 1 atm of dioxygen for 24 h produces [Co(TpivPP)(A(-Meim)(02)] (200).654 The pivalamido pickets in this compound exercise control of solvation about the coordinated dioxygen moiety and the stability is comparable with that of CoMb02,655 where the globin protein environment performs the same function. 

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