A novel butyrylcholinesterase from serum of Leporinus macrocephalus, a Neotropical fish.
We show here that serum of piaussu, a Neotropical characin fish, has the highest butyrylcholinesterase activity so far described for humans and fish. To clarify whether this cholinesterase could protect piaussu against anticholinesterase pesticides by scavenging organophosphates, we purified it 1700-fold, with a yield of 80%. Augmenting concentrations (from 0.01 to 20 mM) of butyrylthiocholine activated it. The pure enzyme was highly inhibited by chlorpyriphos-oxon (ki=10,434x10(6) M-1 min-1) and by the specific butyrylcholinesterase inhibitor, isoOMPA (ki=45.7x10(6) M-1 min-1). Electrophoresis of total serum and 2-D electrophoresis of the purified cholinesterase showed that some enzyme molecules could circulate in piaussu serum as heterogeneously glycosylated dimers. The enzyme's N-terminal sequence was similar to sequences found for butyrylcholinesterase from sera of other vertebrates. Altogether, our data present a novel butyrylcholinesterase with the potential of protecting a fish from poisoning by organophosphates.
Salles
J B
JB
Department of Biochemistry, UERJ, Av. Professor Manuel de Abreu, 444, Rio de Janeiro, RJ 20550-170, Brazil.
Cunha Bastos
V L F
VL
Silva Filho
M V
MV
Machado
O L T
OL
Salles
C M C
CM
Giovanni de Simone
S
S
Cunha Bastos
J
J
D000595:Amino Acid Sequence; D000818:Animals; D002091:Butyrylcholinesterase / Q000097:blood* / Q000302:isolation & purification / Q000378:metabolism; D002092:Butyrylthiocholine / Q000378:metabolism; D004390:Chlorpyrifos / Q000031:analogs & derivatives / Q000494:pharmacology; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D005399:Fishes / Q000097:blood*; D006801:Humans; D008969:Molecular Sequence Data; D062025:Organophosphate Poisoning; D010261:Paraoxon / Q000031:analogs & derivatives / Q000494:pharmacology; D011041:Poisoning / Q000517:prevention & control; D016415:Sequence Alignment; D013770:Tetraisopropylpyrophosphamide / Q000494:pharmacology
D002800:Cholinesterase Inhibitors; D002092:Butyrylthiocholine; D013770:Tetraisopropylpyrophosphamide; C009618:O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphate; D002091:Butyrylcholinesterase; D004390:Chlorpyrifos; D010261:Paraoxon; C008480:methylparaoxon