KAJIAN IN SILICO HUBUNGAN DIMERISASI, AKTIVITAS, DAN RESISTENSI TERHADAP ENZIM PROTEOLITIK PADA CU,ZN SUPEROKSIDA DISMUTASE DARI CITRUS LIMON

• Main Author: Anisa Abdillah, Virgi
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/66095
• Institution: Institut Teknologi Bandung

Cu,Zn superoxide dismutase Citrus limon (SOD_Cl) is an antioxidant and can be used as a therapeutic agent to treat oxidative stress conditions. SOD_Cl is stable at a wide range of pH and resists proteolysis by trypsin and chymotrypsin hence it is a good candidate protein therapeutic administered via oral or topical route. Active SOD_Cl occurs as monomer or dimer, in which is the dimer is 65% more active than the monomer. This study aims to study the relationship between dimerization and activity as well as resistance to trypsin and chymotrypsin in silico. Residue interactions around the active site and at the dimer interface were analyzed using Coot and SpotOn program. The resistance of the SOD_Cl structure to proteolysis was predicted from the value of Solvent Accessible Surface Area (SASA), B-factor, and secondary structure site of protease cleavage. The result showed that the geometry of the active site is stabilized by the amino acid residues Gly43, Gly60, Gly81, Gly123, Gly140, and Gly137. The interactions at the dimer interface of the SOD_Cl are formed by hydrogen bonding and hydrophobic interactions. The residue at the dimer interface is predicted not to be part of the active site SOD_Cl. Hydrophobic interactions at the dimer interface appeared to play role to shape the optimum active side geometry and thereby maintain the enzyme stability. In SOD_Cl there are 9 trypsin cleavage sites and 23 chymotrypsin cleavage sites. SOD_Cl is resistant to trypsin and chymotrypsin proteolysis because of inaccessibility of the cleavage site and structural flexibility.