Hemoglobin fractions

Y-chains which differ from the 3-chalns In 39 positions The formula of Hb-F can be written as a2Y2 A minor hemoglobin fraction, Hb-Fi, which Is present for about 7 to 10 percent In a cord blood sample, has the structure of U2Y2 y Indicating that the NH2 terminal glycyl residue of the y-chaln Is acetylated Recently the existence of two structurally different Y-chalns has been demonstrated these two chains (the -and differ at a minimum In one position, namely... 

Apart from the wide ran of staining techniques, fluore nt and radioactive labels are often used. FITC is used for protein detection following SDS-electrophoresis, e.g. Rat hemoglobin fractions have been assayed by labeling with Double labeling with and makes it possible to detect proteins from two different... 

Other Minor Hemoglobins. The nature of Hb-Aia and Hb-An. has not been clarified. The two minor hemoglobins are present in decreased quantities in patients with hemolytic anemia, and in increased amounts in patients with myelocytic leukemia and iron deficiency anemia (Fig. 7) (H24). An unknown, fast moving, minor hemoglobin fraction has been observed when red cell hemolysates from children with elevated blood lead levels were analyzed by electrophoresis (Cll). 

H45. Huisman, T. H. J., and Horton, B. F., Studies on the heterogeneity of hemoglobin. VIII. Chromatographic and electrophoretic investigations of various minor hemoglobin fractions present in normal and in vitro modified red blood cell hemol-ysates. J. Chromatogr. 18, 116-123 (1965). 

Hasegawa, S., T. Sako, N. Takemura, H. Koyama, and S. Motoyoshi. 1991. Glycated hemoglobin fractions in normal and diabetic dogs measured by high performance hquid chromatography. Journal of Veterinary Medical Science 53 65-68. 

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. 

Apart from its natural occurrence, Co may find its way into other proteins either adventitiously or deliberately. A study was undertaken where the blood, serum, and plasma of workers occupationally exposed to Co were analyzed for the element.1189 When separated by gel electrophoresis under denaturing conditions, the Co fractions in all blood, serum, and plasma samples showed a similar protein pattern. A variety of proteins of differing size were found to bind Co in fractions collected at pFl 5, whereas only hemoglobin was found in the pH 7 fractions. The conclusions were that in vivo Co is bound to plasma proteins, perhaps albumin and hemoglobin. 

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. 

In the initial experiments, we resolved reticulocyte lysates on DEAE-cellulose into two crude fractions Fraction 1, which contained proteins not adsorbed to the resin, and Fraction 2, which contained all proteins adsorbed to the resin and eluted with high salt. The original aim of this fractionation was to get rid of hemoglobin, which was known to be in Fraction 1, while most non-hemoglobin proteins of reticulocytes were known to be in Fraction 2. We found that neither fraction was active by itself, but ATP-dependent protein degradation could be reconstituted by combination of the two fractions [13]. The active component in Fraction 1 was a small, heat-stable protein we have exploited its stability to heat treatment for its purification to near homogeneity. We termed this protein at that time APF-1, for ATP-dependent Proteolysis Factor 1 [13]. The identity of APF-1 with ubiquitin was established later by Wilkinson et al. [14], subsequent to the discovery in my laboratory of its covalent ligation to protein substrates, as described below. 

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