title: Arylamine N-acetyl Transferase (NAT) in the blue secretion of Telescopium telescopium: xenobiotic metabolizing enzyme as a biomarker for detection of environmental pollution.
abstract: Telescopium telescopium, a marine mollusc collected from Sundarban mangrove, belongs to the largest mollusca phylum in the world and exudes a blue secretion when stimulated mechanically. The blue secretion was found to metabolize (preferentially) para-amino benzoic acid, a substrate for N-acetyl transferase (NAT), thereby indicating acetyl transferase like activity of the secretion. Attempts were also made to characterise bioactive fraction of the blue secretion and to further use this as a biomarker for monitoring of marine pollution. NAT like enzyme from marine mollusc is a potential candidate for detoxification of different harmful chemicals. A partially purified extract of blue secretion was obtained by fractional precipitation with (NH4)2SO4. From different fractions obtained by precipitation, the 0-30% fraction (30S) displayed NAT like activity (using para amino benzoic acid as a substrate with para nitrophenyl phosphate or acetyl coenzyme A as acetyl group donors). Maximum NAT like enzyme activity was attained at 25°C and at a pH of 6. The enzyme activity was found to be inhibited by 5 mM phenyl methyl sulfonyl fluoride. The divalent metal ions reduced NAT like activity of 30S. Moreover, Cu(2+) and Zn(2+) (at concentration of 1 mM) completely inhibited NAT activity. The thermal stability and bench-top stability studies were performed and it was found that the enzyme was stable at room temperature for more than 24 hours. Results from the present study further indicate that heavy metal content in blue secretion gradually decreased from pre-monsoon to post-monsoon season, which also corresponded to the change in NAT like activity. Therefore, this article stresses the importance of biomarker research for monitoring pollution.
authors.affiliation: Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032 India.
authors.forename: Bapi
authors.initials: B
authors.lastname: Gorain
authors.affiliation: Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032 India.
authors.forename: Sumon
authors.initials: S
authors.lastname: Chakraborty
authors.affiliation: Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032 India.
authors.forename: Murari Mohan
authors.initials: MM
authors.lastname: Pal
authors.affiliation: Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032 India ; School of Natural Product Studies, Jadavpur University, Kolkata, 700032 India.
authors.forename: Ratul
authors.initials: R
authors.lastname: Sarkar
authors.affiliation: Calcutta Institute of Pharmaceutical Technology and AHS, Banitabla, Ulluberia, Howrah 711316 India.
authors.forename: Samir Kumar
authors.initials: SK
authors.lastname: Samanta
authors.affiliation: Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032 India.
authors.forename: Sanmoy
authors.initials: S
authors.lastname: Karmakar
authors.affiliation: Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032 India ; School of Natural Product Studies, Jadavpur University, Kolkata, 700032 India.
authors.forename: Tuhinadri
authors.initials: T
authors.lastname: Sen