Purification and characterization of deoxyribonuclease from small intestine of camel Camelus dromedarius

• Published in: Journal of Genetic Engineering and Biotechnology 2017-12, Vol.15 (2), p.463-467
• Main Authors: Abdel-Gany, Somia S., El-Badry, Mohamed O., Fahmy, Afaf S., Mohamed, Saleh A.
• Format: Article
• Language: English
• Subjects: Animal Biotechnology; Camel; Deoxyribonuclease; Small intestine
• ISSN: 1687-157X; 2090-5920
• DOI: 10.1016/j.jgeb.2017.06.008

The chromatography of deoxyribonuclease (DNase) from small intestine of camel Camelus dromedarius by DEAE-Sepharose separated three isoforms DNase 1, DNase 2 and DNase 3. The DNase 3 was purified to homogeneity by chromatography on Sephacryl S-200. The molecular weight of DNase 3 was 30kDa using gel filtration and SDS-PAGE. The pH optimum of DNase 3 was reported at 7.0 using Tris-HCl buffer. The temperature optimum of DNase 3 was found to be 50°C. The enzyme was stable up to 50°C for one h incubation. The Km value was 28.5µg DNA, where this low value indicated the high affinity of enzyme toward DNA as substrate. No activity of DNase 3 was determined in the absence of metal cations. Mg2+ and Ca2+ caused significant enhancement in the enzyme activity by 90 and 75%, respectively. The mixture of Mg2+ and Ca2+ caused 100% of enzyme activity. Ni2+, Co2+, Ba2+, Zn2+ and Cd2+ showed very strong inhibitory effect on enzyme activity. In conclusion, the characterization of DNase 3 indicated that the enzyme is considered as a member of DNase I family. The low Km value of the DNA suggested that the high digestion of DNA of camel forage by small intestine DNase 3.