ACTION OF A COMPLEX RADIATION FLUX ON ERYTHROCYTE PHOSPHOMONOESTERASE (in Rumanian)
To study the effect of radiation on the enzyme, erythrocytes were irradiated in the reactor of the Institute of Atomic Physics of the Romanian Academy of Sciences, Bucharest, in which the intensity of the various radiation components is: thermal neutrons 2.3 x 10/sup 7//cm/sup 2//sec, epithermal neutrons 7.1 x 10/sup 5//cm/sup 2//sec, fast neutrons 4.0 x 10/sup 7//cm/sup 2// sec, and gamma radiation 0.06 r/sec. In general, irradiation lowered the enzyme activity of solutions of the enzyme from horse erythrocytes, this reduction depending on the duration of irradiation and the initial enzyme activity. Kinetics of the nonirradiated and irradiated enzyme with respect to its substrate, alpha -glycerophosphate, were studied at various temperatures and substrate concentrations, according to the formulations of Lineweaver and Burk and the Michaelis constant (K/sub m/) was determined. The value of K/sub m/ was 0.0294 and 0.10 mole/l after 30 and 60 min irradiation, respectively, in contrast to 0.04 mole/l for the native enzyme. The corresponding hydrolysis rates at a substrate concentration of 0.50 g/100 ml were 0.036, 0.025, and 0.045, as g P per 100 ml erythrocytes at 37 deg C. Impairment of quality of the enzyme during irradiation was shown by the progressive increase in activation energy, which rose from 8955 cal/mole in native enzyme to 11500 and 11666 cal/mole in solutions of enzyme irradiated for 15 and 30 min, respectively. Although the above data apply to the equine enzyme only, similar changes in kinetics were observed following irradiation of the enzyme in bovine erythrocytes. (BBB)
- Research Organization:
- Facultatea de Medicina Veterinara; and Institutul de Fizica Atomica, Bucharest
- NSA Number:
- NSA-17-038751
- OSTI ID:
- 4634719
- Journal Information:
- Acad. Rep. Populare Romine, Studii Cercetari Biochim., Vol. Vol: 4; Other Information: Orig. Receipt Date: 31-DEC-63
- Country of Publication:
- Country unknown/Code not available
- Language:
- Rumanian
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