http://nopr.niscair.res.in/handle/123456789/3270 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/3409 Title: Photoilluminated riboflavin/riboflavin-Cu(II) inactivates <br/> <br/>Authors: Husain, E; Fatima, R A; Ali, I A F; Naseem, I <br/> <br/>Abstract: Riboflavin (RF) upon irradiation with fluorescent light generates reactive oxygen species like superoxide anion, singlet and triplet oxygen, flavin radicals and substantial amounts of hydrogen peroxide (H2O2). H2O2 can freely penetrate cell membrane and react with a transition metal ion like Cu(II), generating hydroxyl radical via the modified metal-catalyzed Haber-Weiss reaction. Earlier, it was reported that trypsin-chymotrypsin mixture served as an indirect antioxidant and decreased free radical generation. Thus, in the present study, we used photoilluminated RF as a source of ROS to investigate the effect of free radicals on the activity of trypsin. We also compared the damaging effect of photoilluminated RF and RF-Cu(II) system using trypsin as a target molecule. RF caused fragmentation of trypsin and the effect was further enhanced, when Cu(II) was added to the reaction. Results obtained with various ROS scavengers suggested that superoxide radical, singlet and triplet oxygen were predominantly responsible for trypsin damage caused by photoilluminated RF. On the other hand, when Cu(II) was added to the reaction, hydroxyl radical was mainly responsible for trypsin damage. A mechanism of generation of various ROS in the reaction is also proposed. Trypsin did not show any antioxidant effect with RF alone or with RF–Cu(II) combination. <br/> <br/>Page(s): 312-318 Sat, 29 Oct 2005 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/3408 Title: Isolation and identification of α-amylase producing Bacillus sp. from dhal industry waste <br/> <br/>Authors: Thippeswamy, S; Girigowda, K; Mulimani, V H <br/> <br/>Abstract: A bacterial strain was isolated from dhal industry red gram waste and identified as Bacillus. A thermostable extracellular amylase was partially purified from the strain. Optimum temperature and pH for the enzyme were found to be 60C and 6.5, respectively. The maximum amylase production was achieved with maltose as carbon source. Among the nitrogen sources, peptone and yeast extract produced maximum amylase. <br/> <br/>Page(s): 295-298 Sat, 29 Oct 2005 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/3407 Title: Extraction and carrier-facilitated transport of amino acids using synthetic non-cyclic receptors through bulk liquid membrane <br/> <br/>Authors: Joshi, Pratibha; Joshi, Nidhi; Sharma, Uma <br/> <br/>Abstract: The extraction and carrier-facilitated transport of amino acids (leucine, valine and glycine) was studied through chloroform bulk liquid membrane system using a series of non-cyclic receptors such as diethylene glycol (1), diethylene glycol dimethyl ether (2), diethylene glycol dibutyl ether (3), diethylene glycol dibenzoate (4), triethylene glycol (5) and tetraethylene glycol (6). The amount of amino acid extracted and transported depends mainly upon the structure and the concentration of the receptors and also on the concentration of amino acid. The receptors 1 to 4, having small chain length and flexible end groups, formed stable complexes with amino acids, and the flexibility of receptors in different conformational forms was responsible for their carrier ability, while the receptors 5 and 6, having larger chain length showed poor carrier ability. Hydrophobicity of amino acids also play an important role in the extraction as well as transport process. <br/> <br/>Page(s): 323-326 Sat, 29 Oct 2005 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/3406 Title: Hypolactasia as a molecular basis of lactose intolerance <br/> <br/>Authors: Kaur, Kamaljit; Mahmood, Safrun; Mahmood, Akhtar <br/> <br/>Abstract: Lactase-phlorizin hydrolase (LPH), a membrane-bound glycoprotein present in the luminal surface of enterocytes in the intestine is responsible for lactose intolerance, a phenomenon prevalent in humans worldwide. In the rodent intestine, the post-natal development of the LPH follows a specific pattern, such that the enzyme levels are high in the peri-natal period, but declines considerably upon maturation. The observed maturational decline in the LPH activity is very similar to adult-type hypolactasia observed in humans. Majority of the studies have been carried out using animal models or cell lines and a number of hypotheses have been put forward to explain the maturational decline of lactase activity such as: (a) decreased amount of lactase protein, (b) defect in post-translational modification of precursor lactase to the mature enzyme, and (c) synthesis of an inactive, high molecular weight lactase with altered glycosylation, however, the precise underlying mechanism of adult-type hypolactasia remains undefined. The present review describes the recent developments in understanding the regulation of lactase expression and the possible mechanism of adult-type hypolactasia, as a cause of lactose intolerance. <br/> <br/>Page(s): 267-274 Sat, 29 Oct 2005 22:58:59 GMT