- Monday, October 23, 2006
- Published at:Indian J Biochem Biophys
- Indian J Biochem Biophys. 2006 Oct;43(5):312-8.
Photoilluminated riboflavin/riboflavin-Cu(II) inactivates trypsin: Cu(II) tilts the balance.
Husain E, Fatima RA, Ali IA, Naseem I.
Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202 002 (U.P.), India.
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(ll), 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
- Saturday, August 12, 2006
- Published at:Med Sci Monit
- Med Sci Monit. 2006 Aug;12(8):BR283-9. Epub 2006 Jul 12.
Photodynamic inactivation of trypsin by the aminophylline-riboflavin system: involvement of hydroxyl radical.
Hasan N, Ali I, Naseem I.
Department of Biochemistry, Faculty of Medicine, J.N. Medical College, Aligarh Muslim University, Aligarh, India [email protected]
BACKGROUND: Riboflavin finds ubiquitous occurrence in plants and animals and functions as a coenzyme participating in various oxidation-reduction reactions during the course of metabolism. Photosensitized riboflavin generates reactive oxygen species (ROS). Aminophylline is an antiasthmatic drug and a known phosphodiesterase inhibitor. In this study we examined the effect of photoilluminated riboflavin on aminophylline using trypsin as the target molecule.
MATERIAL/METHODS: The possible loss of trypsin activity due to autolysis was assayed after incubation in fluorescent light. Changes in trypsin activity caused by photoilluminated
- Friday, September 23, 2005
- Published at:Biochemistry (Mosc)
- Biochemistry (Mosc). 2005 Sep;70(9):1011-4.
Hemolysis of human red blood cells by riboflavin-Cu(II) system: enhancement by azide.
Ali I, Sakhnini N, Naseem I.
Faculty of Pharmacy, Applied Science University, Amman, Jordan. [email protected]
Photoactivated riboflavin in the presence of Cu(II) generates reactive oxygen species (ROS) which can hemolyze human red blood cells (RBC). In the present work we examined the effect of sodium azide (NaN3) on RBC in the presence of riboflavin and Cu(II). The addition of NaN3 to the riboflavin-Cu(II) system enhanced K+ loss and hemolysis. The extent of K+ loss and hemolysis were time and concentration dependent. Bathocuproine, a Cu(I)-sequestering agent, inhibited the hemolysis completely. Among various free radical scavengers used to identify the major ROS involved in the reaction, thiourea was found to be the most effective scavenger. Thiourea caused almost 85% inhibition of hemolysis suggesting that *OH is the major ROS involved in the re
- Tuesday, August 23, 2005
- Published at:Saudi Pharmaceutical Journal
- Nina Sakhnini*, Iyad Ali and Samar Khater.
Synthesis of a novel b-Lactamase hydrolysis resistant penicillin analog.
Saudi Pharmaceutical Journal, 2005, 13, 83-88. Saudi Arabia
- Wednesday, February 23, 2005
- Published at:Arab Journal of Pharmaceutical Sciences
- Iyad Ali and Imrana Naseem.
The effect of riboflavin-Cu(II) system on lipid peroxidation of human red blood cells.
Arab Journal of Pharmaceutical Sciences, 2005, 2, 11-20. Damascus