Characterization of two thermostable inulinases from Rhizopus oligosporus NRRL 2710

Two inulinases (Inu2 and Inu3) were purified from Rhizopus oligosporus NRRL 2710 by chromatography on DEAE-Sepharose and Sephacryl S-200 columns. The molecular weight of Inu2 and Inu3 were determined to be 76 and 30 kDa, respectively. Inu2 and Inu3 had the same pH optimum at 5.0, temperature optimum at 50 and 60 °C, and thermal stability up to 60 and 70 °C for 1 h, respectively. Inu2 and Inu3 had low km values (0.93 and 0.70 mM, respectively) indicating the high affinity toward inulin. Mg2+, Ca2+, Zn2+ and EDTA did not significantly influence the enzyme activity. Ni2+, Cu2+, Fe2+ and Co2+ showed a partial inhibitory effect, and Hg2+ had a strong inhibitory effect. p-Chloromercuribenzoate had a partial inhibitory effect on Inu2. From these findings, R. oligosporus inulinases can be beneficial enzymes for industrial enzymatic production of high fructose syrup

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

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 30 kDa 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 28.5 µg 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

Development of novel delivery system for nanoencapsulation of catalase: formulation, characterization, and <i>in vivo</i> evaluation using oxidative skin injury model

<p>One of the main challenges for successful pharmaceutical application of Catalase (CAT) is maintaining its stability. Physical immobilization of CAT through nano-encapsulation was proposed to resolve this challenge. CAT encapsulating niosomes (e-CAT) were prepared using Brij^® 30, 52, 76, 92, and 97 in the presence of cholesterol (Ch) by thin film hydration method. Niosomes were characterized for encapsulation efficiency % (EE), size, poly-dispersity index (PI), and morphology. Kinetic parameters, pH optimum, thermal stability, and reusability of CAT were determined. The influence of optimized e-CAT dispersion onto thermally injured rat skin was evaluated. Results revealed that encapsulation enhanced CAT catalytic efficiency (<i>V</i>_max/<i>K</i>_m). Free CAT and e-CAT had pH optimum at 7.0. e-CAT exhibited improved thermal stability where it retained 50% residual activity at 60 °C. Free CAT lost its activity after three consecutive operational cycles; however, e-CAT retained 60% of its initial activity following 12 cycles. After 24 h of topical application on thermal injury, a significant difference in lesion size was observed with e-CAT compared with the control group. Based on these encouraging results, CAT immobilization demonstrated a promising novel delivery system that enhances its operational stability. In addition, nano-encapsulated CAT can be anticipated to be beneficial in skin oxidative injury.</p

Ficus carica, Ficus sycomorus and Euphorbia tirucalli latex extracts: Phytochemical screening, antioxidant and cytotoxic properties

status: publishe

Purification and characterization of pectin methylesterase isoenzymes from orange peel

No Abstract. The Egyptian Journal of Biochemistry and Molecular Biology Vol. 24(1) 2006: 73-9