title: Antibacterial serine protease from Wrightia tinctoria: Purification and characterization.
abstract: A serine protease was purified from the leaves of Wrightia tinctoria by sequential flow through method comprising screening, optimization, ammonium sulfate precipitation, gel filtration and ion exchange column chromatography. The yield and purification fold obtained were 11.58% and 9.56 respectively. A single band of serine protease was visualized on SDS-PAGE and 2-D gel electrophoretic analyses were revealed with the molecular mass of 38.5 kDa. Serine protease had an optimum pH of 8.0 and was stable at 45°C with high relative protease activity. The addition of metal ions such as Mg2+ and Mn2+ exhibits a high relative activity. Serine protease had a potent antibacterial activity against both Gram-positive and Gram-negative bacteria. A 10 μg/ml of serine protease was tested against S. aureus, M. luteus, P. aeruginosa and K. pneumoniae which had 21, 20, 18 and 17 mm of zone of inhibition respectively. Serine protease from W. tinctoria degrades the peptidoglycan layer of bacteria which was visualized by transmission electron microscopic analysis.
authors.affiliation: Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai 600025, Tamilnadu, India. Electronic address: saktthivel@gmail.com.
authors.forename: Sakthivel
authors.initials: S
authors.lastname: Muthu
authors.affiliation: Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai 600025, Tamilnadu, India.
authors.forename: Venkatesh Babu
authors.initials: VB
authors.lastname: Gopal
authors.affiliation: Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai 600025, Tamilnadu, India.
authors.forename: Selvakumar
authors.initials: S
authors.lastname: Soundararajan
authors.affiliation: Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai 600025, Tamilnadu, India.
authors.forename: Karthikeyan
authors.initials: K
authors.lastname: Nattarayan
authors.affiliation: Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai 600025, Tamilnadu, India.
authors.forename: Karthik
authors.initials: K
authors.lastname: S Narayan
authors.affiliation: Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai 600025, Tamilnadu, India.
authors.forename: Mythileeswari
authors.initials: M
authors.lastname: Lakshmikanthan
authors.affiliation: Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai 600025, Tamilnadu, India.
authors.forename: Sathuvan
authors.initials: S
authors.lastname: Malairaj
authors.affiliation: Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai 600025, Tamilnadu, India. Electronic address: palanii7@yahoo.com.
authors.forename: Palani
authors.initials: P
authors.lastname: Perumal
mesh_terms: D000645:Ammonium Sulfate / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000302:isolation & purification* / Q000494:pharmacology; D029062:Apocynaceae / Q000201:enzymology*; D001419:Bacteria / Q000187:drug effects / Q000648:ultrastructure; D002021:Buffers; D002463:Cell Membrane Permeability / Q000187:drug effects; D011232:Chemical Precipitation; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007477:Ions; D008670:Metals / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008970:Molecular Weight; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000201:enzymology; D011480:Protease Inhibitors / Q000494:pharmacology; D057057:Serine Proteases / Q000302:isolation & purification*; D012997:Solvents / Q000494:pharmacology; D013379:Substrate Specificity / Q000187:drug effects; D013696:Temperature
chemical_list: D000900:Anti-Bacterial Agents; D002021:Buffers; D007477:Ions; D008670:Metals; D010936:Plant Extracts; D011480:Protease Inhibitors; D012997:Solvents; D057057:Serine Proteases; D000645:Ammonium Sulfate
keywords: Antibacterial activity; Leaves; Seine protease; Wrightia tinctoria