Investigating the thermodynamic and kinetics properties of acid phosphatase extracted and purified from seedlings of Chenopodium murale.

Herein acid phosphatase isoenzyme was extracted from the C. murale seedlings. The purification was accomplished by chromatographic techniques and passing through DEAE-cellulose and Sephadex G-100 column. The specific activity of acid phosphatase 5.75 U/mg of protein was obtained with 66 purification fold 15.8% yield and molecular mass was 29 kDa with very faint bands corresponding to 18 kDa and 14 kDa. The maximal activity at pH 5.0 and 50 °C best illustrated by first order kinetics. When temperature was raised (55 °C to 75 °C), the deactivation rate constant was increased from 0.001 to 0.014 min-1, while half-life was decreased from 693 to 49 min-1. The results of activity collected at different temperature were then used to estimate, activation energy of hydrolysis reaction (Ea = 47.59 kJmol-1). A high Z-value (18.86 °C min-1) was obtained indicating a less sensitivity towards temperatures. The residual activity examinations were carried out from 55 °C to 75 °C and assessing the Deactivation Energy (Ed 116.39 kJmol-1), Enthalpy change (ΔH° 113.55kJmol-1), Entropy change (ΔS° 110.33kJmol-1) and change in Gibbs free energy (ΔG° 10.02 kJmol-1). Taken together, thermodynamic parameters confirm the high stability of enzyme and show potential commercial applicability.

Antibacterial, antifungal, antispasmodic and Ca++ antagonist effects of Caesalpinia bonducella.

Caesalpinia bonducella F. (Leguminosae) has been used as a folk medicine for a variety of ailments. The crude extract of C. bonducella and its fractions were studied for antibacterial, antifungal, antispasmodic and Ca++ antagonistic properties. The strongest antibacterial effect was displayed by the n-butanol (72%) and ethyl acetate (80%) fractions, followed by the crude extract (46% and 42%), against Escherichia coli and Bacillus subtilis, respectively. The plant extract and its fractions showed mild to excellent activity in antifungal bioassays, with maximum antifungal activity against Candida glaberata (80%) and Aspergillus flavus (70%) by the n-butanol and chloroform fractions, followed by the crude extract (70% and 65%). Caesalpinia bonducella extract caused concentration-dependent inhibition of spontaneous and high K+ (80 mM)-induced contractions of isolated rabbit jejunum preparations, similar to that caused by Verapamil. These results indicate that C. bonducella exhibits antibacterial, antifungal, spasmolytic and Ca++ channel blocking actions.

Purification and biochemical characterization of alkaline serine protease from Caesalpinia bonducella.

A high molecular weight serine protease has been purified to electrophoretic homogeneity from the seeds of Caesalpinia bonducella Flem. (Caesalpiniaceae) by the combination of size exclusion and ion exchange chromatography. About 524 fold purification was achieved with an overall recovery of 6.8%. The specific activity was found to be 86 U/mg/min at pH 8.0. The calculated K(m) and V(max) were 1.66 mg/mL and 496.68 units/min per mg of protein, respectively. The molecular mass was estimated to be about 63 kDa by sodium dodecyl sulfate PAGE. The enzyme showed optimum activity at pH 8.0 and exhibited its highest activity at 40 degrees C. The enzyme was strongly inhibited by 2mM phenylmethylsulfonyl fluoride (PMSF), suggesting the presence of a serine residue at the active site. PMSF showed a pure competitive type of inhibition with the serine protease enzyme. It was observed that enzyme activity was enhanced in the presence of dications and was active against a variety of modified substrates and natural proteins.