NOPR Collection:

Evaluation of hepatoprotective potential of propolis extract in carbon tetrachloride induced liver injury in rats

2005-10-01T00:00:00Z

Title: Evaluation of hepatoprotective potential of propolis extract in carbon tetrachloride induced liver injury in rats Authors: Shukla, Sangeeta; Bhadauria, Monika; Jadon, Anjana Abstract: Propolis (bee glue), a resinous wax-like beehive product has been used since ancient times for its pharmaceutical properties. In the present study, the ethanolic extract of propolis (50, 100, 200 and 400 mg/kg, p.o.) was studied for its hepatoprotective activity against carbon tetrachloride (CC1₄, 1.5 ml/kg, i.p.) induced liver damage in rats. Administration of CCl₄ caused a sharp elevation in the activity of serum transaminases, serum alkaline phosphatase, acid phosphatase and hepatic lipid peroxidation (LPO) levels, and a significant decrease in the ATPase, alkaline phosphatase and succinic dehydrogenase activities in the liver and kidney and hepatic GSH level. The treatment with propolis extract at the doses of 200 and 400 mg/kg significantly reversed the various biochemical alterations in blood, liver and kidney induced by CCl₄ intoxication. The hepatoprotective property of propolis maybe due to its antioxidant activity. Page(s): 321-325

Purification and characterization of α-amylase from Bacillus amyloliquefaciens NCIM 2829

2005-10-01T00:00:00Z

Title: Purification and characterization of α-amylase from Bacillus amyloliquefaciens NCIM 2829 Authors: De, Mithu; Das, Kali P; Chakrabartty, P K Abstract: α-Amylase (EC 3.2.1.1) was purified to homogeneity (specific activity 58,000 µmole min^-1 mg protein^-1) from the culture filtrate of Bacillus amyloliquefaciens NCIM 2829. Its molecular mass was found to be 67.5 kDa. The activity of the enzyme increased by almost 50% in the presence of Co⁺² ion. Hg⁺² and Cu⁺² acted as strong inhibitors of the enzyme. The tryptophan moities of the enzyme were fairly protected from the aqueous environment. However, the globular interior of the protein was somewhat loosely packed. The protein had nearly an equal amount of α-helical and β-sheet structure in dilute solution. In concentrated solution, its secondary structure had a higher proportion of β-sheet at the expense of some random coil structure. The protein showed a molten globule state at a low concentration of chaotropic agent. The denaturation profile of the protein showed no cooperativity. Co²⁺ enhanced the structural stability of the enzyme. Page(s): 287-294

Crystal structure of a novel phospholipase A₂ from crude venom of Indian cobra sub-species Naja naja sagittifera at 1.48 Ǻ resolution

2005-10-01T00:00:00Z

Title: Crystal structure of a novel phospholipase A₂ from crude venom of Indian cobra sub-species Naja naja sagittifera at 1.48 Ǻ resolution Authors: Singh, Rajendra K; Jabeen, Talat; Sharma, Sujata; Kaur, Punit; Srinivasan, A; Singh, Tej P Abstract: Secretory phospholipase A₂s (PLA₂s), the structurally-homologous enzymes share a common qualitative catalytic site, but differ greatly in their pharmacological properties and toxicities. There has been a recognizable pattern of mutations in the primary sequence of PLA₂s that alter their catalytic properties significantly. In the present study, the amino acid sequence and the three-dimensional structure of a new isoform of PLA₂ from crude venom of Indian cobra sub-species Naja naja sagittijera (N.n.s.) has been determined by X-ray crystallography. The crystal structure has revealed several novel features of PLA₂ folding and furiction. It contains 913 protein atoms and one each of Ca²⁺, phosphate and acetate ions with 142 solvent water molecules. A Ca²⁺ ion is present in the calcium-binding loop and forms a seven-fold coordination with a distorted" pentagonal bipyramidal geometry. One of the coordination linkages is with the acetate ion, instead of the conserved water molecule. The presence of Lys at position 31 has a stabilizing effect on the loop Tyr 25-Cys 29 by interacting 'with carbonyl oxygen atoms of Tyr 25, Gly 26 and Cys 29. In turn, it lends stability to the Ca²⁺-binding loop as well. Another unique feature of the PLA₂ structure is the formation of an intrastrand hydrogen bond, involving Oγ of Thr 73 and Oɛ2 of Glu 71, thus helping the β-wing to act as a sharp arrow for insertion into other molecules. Yet another important feature of this PLA₂ pertains to the conformation of its C-terminal segment, which is stabilized by a unique hydrogen bond through carbonyl oxygen of Lys 116 and Nδ2 of Asn 120. This structural feature may be useful in the molecular recognition of the PLA₂ through C-terminal segment. Page(s): 279-286

CDC27 protein is involved in radiation response in squamous cell cervix Carcinoma

2005-10-01T00:00:00Z

Title: CDC27 protein is involved in radiation response in squamous cell cervix Carcinoma Authors: Rajkumar, T; Gopal, G; Selvaluxrni, G; Rajalekshmy, K R Abstract: In the present study, an attempt was made to identify genes involved in radiatiorr response in cervix carcinoma. Differential display technique was used to study the expression profiles of tumour biopsy samples obtained from patients, responding and not responding to treatment. The samples were obtained prior to radiotherapy and subsequent to treatment with Tele-radiation at 10 Gray (Gy). One of the differentially expressed cDNAs, when sequenced was identified to be CDC27. Immuno-histochemical analysis of pre- and post-treated tumour samples from fifteen patients showed the downregulation of expression of CDC27 protein in seven patients. Down-regulation was associated with poorer response to radiotherapy. Cervical cancer cell lines SiHa and C33A were irradiated and their nuclei were stained for expression of CDC27 and analyzed using fluorescent-activated cell sorting (FACS). Down-regulation of CDC27 protein in the irradiated SiHa cell line was associated with greater survival fraction, compared to the irradiated C33A cell line, which had only slight fall in the level of CDC27 protein. This is the first study to suggest a role for CDC27 in radiation response. However, a larger cohort is needed to further confirm the value of CDC27 protein as a predictive marker, for radiation response in cervix cancer. Page(s): 271-278

NOPR Collection:

Evaluation of hepatoprotective potential of propolis extract in carbon tetrachloride induced liver injury in rats

Purification and characterization of α-amylase from Bacillus amyloliquefaciens NCIM 2829

Crystal structure of a novel phospholipase A2 from crude venom of Indian cobra sub-species Naja naja sagittifera at 1.48 Ǻ resolution

CDC27 protein is involved in radiation response in squamous cell cervix Carcinoma

Crystal structure of a novel phospholipase A₂ from crude venom of Indian cobra sub-species Naja naja sagittifera at 1.48 Ǻ resolution