Modifications of aldolase during in vivo aging of rabbit red cells.

Crude hemolysates, partially purified aldolase and aldolase purified to homogeneity from reticulocytes and mature erythrocytes, were incubated with a specific antiserum raised against crystalline rabbit muscle aldolase. We show that the same aldolasic activity corresponds to a greater amount of antigen in older than in younger cells, in crude hemolysates as well as in the above mentioned preparations; that is to say, old-cell aldolase contains cross-reacting material (CRM). Properties of purified enzyme from reticulocytes and mature erythrocytes were compared to those of muscle crystalline aldolase: -- the molecular specific activity of purified aldolase from erythrocytes is lower than with crystalline muscle aldolase, i.e. CRM is maintained throughout the purification steps. -- the specific activity of red cell aldolase towards both substrates (FDP and F1P) is lower than that of crystalline muscle aldolase. However, the ratio of activity towards the two substrates FDP/F1P is decreased in erythrocytes and reticulocytes. -- no other difference was found: Michaelis constant towards FDP, thermodenaturation constant and C terminal extremities are identical as are the molecular weights.

[Hemoglobin Pyrgos beta 83 (EF 7) Gly leads to Asp in a Malian: structural identification and functional properties (author's transl)]. / Hémoglobine Pyrgos beta 83 (EF 7) Gly leads to Asp chez un Malien: identification structurale et propriétés fonctionnelles.

The second observation of hemoglobin Pyrogos is reported. This abnormality was initially described in a Greek family, in our case it concerns an African negro originating from the Republic of Mali. The abnormal hemoglobin was without clinical or hematological consequences. The structural defect is a substitution of an Asp for a Gly in the immediate vicinity of lysine beta 82. This leads to a large inhibition of the corresponding tryptic cleavage and therefore to difficulties in the determination of the mutation. A second feature is a slight modification occurring near one of the 2.3 DPG binding site. As a consequence, the regulatory effect of this organic phosphate is smaller in the purified and stripped component than on hemoglobin A.