دراسة كيموحياتية لإنزيم الكايتينيز و علاقته بالثلاسيميا

الملخص EN

The present research is a clinical study of chitinase and its relation with thalassemia.

It had been found that the normal range of chitinase activity in serum of healthy control (1.79 ± 0.10 U / ml), and it had been found that significant decrease of chitinase activity for patients group when compared with controls group.

It was also found that the activity was not affected by sex whereas an increase was found with aging in both patients and control groups.

The result demonstrated that the chitinase activity was not affected by the type of thalassemia (α or β - thalassemia), distress of β- thalassemia (major and intermediate) and splenctomy.

The results show a significant increase in (GPT), (GOT), (Fe) and (TIBC) while also showed a significant decrease in hemoglobin level of thalassemia patients compared with control.

Correlation coefficient between chitinase activity and clinical variables of thalassemia patients studied showed a significal reversible relation between chitinase and (Fe) and irreversible relation between chitinase and (GPT) in control.

It also show a reversible relation between chitinase and hemoglobin in patients.

The isolation method of chitinase from lysosome of plasma (protein peak B) showed two protein peaks by gel filtration technique, using column containing sephadex G-75.

The activity of a chitinase showed in(protein peak B).while the isolation method of chitinase from ammonium sulphate solution (75 %) saturation of plasma showed three protein peaks by gel filtration technique, using same column.

The activity of a chitinase showed in (protein peak E), a high number of purification showed in (protein peak B) compared with (protein peak E), it was found that the two peaks (B and E) had apparent molecular weight (39180 ± 1000 dalton) and (36307 ± 1000 dalton) respectively.

The study of the optimum condition of chitinase activity in the two peaks show an optimum reaction time at (35), (30) minute, optimum pH at (7), optimum temperature at (60°C), (55°C), optimum concentration of substrate colloidal chitin (12 mg / ml), (10 mg / ml), Vmax (2.08 U / ml), (2.00 U / ml) and Km(2.12 mg / ml) and (2.00 mg / ml) respectively.

Finally the biological activity had been improved for the isolated chitinase from plasma (for B and E peak) upon the growths of some bacteria and fungi pathogen, it had been found that the enzyme had the ability to inhibit its growth at ratio (100 %) for peak (B) and (50 %) for peak (E).