http://nopr.niscair.res.in/handle/123456789/3449 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/3511 Title: Effects of metal ions and an inhibitor on the fluorescence and activity of acutolysin A from Agkistrodon acutus venom <br/> <br/>Authors: Liu, Xianghu; Xu, Xiaolong; Chen, Jiexia; Liu, Wenqi; Liu, Qingliang <br/> <br/>Abstract: Acutolysin A, a protein isolated from the venom of Chinese Five-pace snake (Agkistrodon acutus) has shown marked hemorrhagic and proteolytic activities. In the present study, the effects of metal ions and an inhibitor EDTA on the fluorescence and function of autolysin A have been studied, by following fluorescence and activity measurements. Acutolysin A contains a Ca²⁺-binding site, which provides it with important structural stability, and a Zn²⁺-binding site, which is essential for its enzymatic activities. The removal of metal ions in acutolysin A by incubation with EDTA results in irreversible inhibition and complete denaturation, and a marked decrease in its fluorescence intensity. The fluorescence intensity of acutolysin A is also decreased in the presence of Cu²⁺, Co²⁺, Mn²⁺ or Mg²⁺, but does not change in the presence of Ca²⁺, Cd²⁺, or Tb³⁺. Caseinolytic activity of acutolysin A is enhanced by Co²⁺, Ca²⁺ and Mg²⁺, but is partly inhibited by Cu²⁺, Mn²⁺ and Tb³⁺, and completely inhibited by Cd²⁺. Both Zn²⁺ and Co²⁺ recover the loss of activity of the protein caused by Cd²⁺. <br/> <br/>Page(s): 100-105 http://nopr.niscair.res.in/handle/123456789/3510 Title: Apolipoproteins and their role in different clinical conditions: An overview <br/> <br/>Authors: Irshad, M; Dubey, R <br/> <br/>Abstract: Apolipoproteins or apoproteins are a group of proteins associated with lipoproteins in different proportions and play significant roles in several diseases. Different types of apolipoproteins, including apolipoproteins A, B, C, D, E, H and J and their subclasses have been reported, in addition to a few more apolipoproteins reported recently. These proteins have varied, but definite roles in normal physiology in our body. Moreover, their blood levels have strong association with clinical conditions during different diseases and are used as diagnostic and prognostic markers and to compute index of risk for some serious disease entities. Present article gives an overview of the structural features, physiological significance and diagnostic and clinical implications of apolipoproteins. <br/> <br/>Page(s): 73-80 http://nopr.niscair.res.in/handle/123456789/3509 Title: Role of a protein inhibitor isolated from human renal stone matrix in urolithiasis <br/> <br/>Authors: Aggarwal, S; Tandon, C; Forouzandeh, M; Singla, S K; Kiran, R; Jethi, R K <br/> <br/>Abstract: The role of biomolecule(s) from renal stone matrix in urolithiasis was investigated. The ability of a particular fraction (>10 kDa fraction) isolated from the EDTA extract of powdered human renal stones to influence calcium oxalate monohydrate (COM) crystal growth was studied. The most potent inhibitor of COM crystal growth obtained from >10 kDa fraction was purified by various chromatographic techniques and SDS-PAGE, etc. and was found to have a molecular mass of 36 kDa. The urine and serum samples obtained from normal persons were found to be more potent in inhibiting the growth of COM crystals as compared to the kidney-stone patients. Polyclonal antibodies were raised against this inhibitor and were employed to determine the concentration of 36 kDa inhibitor in urine and serum samples of normal persons and kidney-stone patients. <br/> <br/>Page(s): 113-117 http://nopr.niscair.res.in/handle/123456789/3508 Title: Exploring selectivity requirements for COX-2 versus COX-1 binding of 2-(5-phenyl-pyrazol-1-yl)-5-methanesulfonylpyridines using topological and physico-chemical parameters <br/> <br/>Authors: Chakraborty, Santanu; Sengupta, Chandana; Roy, Kunal <br/> <br/>Abstract: Considering the current need for development of selective cyclooxygenase-2 (COX-2) inhibitors, an attempt has been made to explore physico-chemical requirements of 2-(5-phenyl-pyrazol-1-yl)-5-methanesulfonylpyridines for binding with COX-1 and COX-2 enzyme subtypes and also to explore the selectivity requirements. In this study, E-states of different common atoms of the molecules (calculated according to Kier & Hall), first order valence connectivity and physico-chemical parameters (hydrophobicity π, Hammett σ and molar refractivity MR of different ring substituents) were used as independent variables along with suitable dummy parameters in the stepwise regression method. The best equation describing COX-1 binding affinity [n = 25, Q² = 0.606, Ra²= 0.702, R² = 0.752, R = 0.867, s = 0.447, F = 15.2 (df 4, 20)] suggests that the COX-1 binding affinity increases in the presence of a halogen substituent at R₁ position and a p-alkoxy or p-methylthio substituent at R₂ position. Furthermore, a difluoromethyl group is preferred over a trifluoromethyl group at R position for the COX-1 binding. The best equation describing COX-2 binding affinity [n = 32, Q² = 0.622, Ra²= 0.692, R² = 0.732, R = 0.856, s = 0.265, F = 18.4 (df 4, 27)] shows that the COX-2 binding affinity increases with the presence of a halogen substituent at R₁ position and increase of size of R₂ substituents. However, it decreases in case of simultaneous presence of 3-chloro and 4-methoxy groups on the phenyl nucleus and in the presence of highly lipophilic R₂ substituents. The best selectivity relation [n = 25, Q² = 0.455, Ra²= 0.605, R² = 0.670, R = 0.819, s = 0.423, F = 10.2 (df 4, 20)] suggests that the COX-2 selectivity decreases in the presence of p-alkoxy group and electron-withdrawing para substituents at R₂ position. Again, a trifluoro group is conducive for the selectivity instead of a difluoromethyl group at R position. Furthermore, branching may also play significant role in determining the selectivity as evidenced from the connectivity parameter. <br/> <br/>Page(s): 106-112