Has a broad substrate specificity. Hydrolyzes various p-nitrophenyl phosphates, aromatic esters and p-nitrophenyl fatty acids in vitro. Most active against paraoxon, phenyl acetate and p-nitrophenyl caproate (C6), respectively. Has also tributyrinase activity, but shows no hydrolytic activity toward other triacylglycerols including tricaprylin, trimyristin, tripalmitin or triolein in vitro. a phenyl acetate + H2O = a phenol + acetate + H(+) An aryl dialkyl phosphate + H2O = dialkyl phosphate + an aryl alcohol. Completely inhibited by chemical modifiers that are specific to Cys (HgCl(2) and p-chloromercuribenzoic acid), His (diethyl pyrocarbonate) and Ser (diisopropyl fluorophosphate and phenylmethanesulfonyl fluoride). No significant effect with chemical modifiers specific to Lys (pyridoxal 5'-phosphate) and Arg (phenylglyoxal). Not inhibited by inhibitors of A-esterases (paraoxon) or C-esterases (physostigmine/eserine). Activity is also not effected by incubation with 5 mM divalent cations for 30 minutes at 30 degrees Celsius or with 10 mM EDTA for 60 minutes at 75 degrees Celsius. kcat is 521 sec(-1) with PA as substrate. kcat is 450 sec(-1) with alpha-NA as substrate. kcat is 285 sec(-1) with p-nitrophenyl butyrate (C4) as substrate. kcat is 467 sec(-1) with p-nitrophenyl caproate (C6) as substrate. kcat is 410 sec(-1) with p-nitrophenyl caprylate (C8) as substrate. kcat is 341 sec(-1) with p-nitrophenyl caprate (C10) as substrate. kcat is 264 sec(-1) with p-nitrophenyl laurate (C12) as substrate. kcat is 265 sec(-1) with p-nitrophenyl palmitate (C16) as substrate. kcat is 269 sec(-1) with p-nitrophenyl phosphate as substrate. kcat is 597 sec(-1) with paraoxon as substrate. kcat is 342 sec(-1) with methyl paraoxon as substrate. Optimum pH is 7.0. Optimum temperature is 94 degrees Celsius. Very thermostable, but rapidly inactivated above 94 degrees Celsius. Most of the activity is retained for 5 days at 50 degrees Celsius, and approximately 70% of the activity is retained after 5 days at 70 degrees Celsius. 52% of the activity is still retained after 50 hours at 90 degrees Celsius, but completely inactivated after 5 days at 90 degrees Celsius. Monomer. Belongs to the 'GDXG' lipolytic enzyme family.