TY - JOUR
T1 - Escherichia coli LT enterotoxin subunit a demonstrates partial toxicity independent of the nicking around Arg192
AU - Tsuji, Takao
AU - Kato, Michio
AU - Kawase, Hidetsugu
AU - Imamura, Seiji
AU - Kamiya, Hirofumi
AU - Ichinose, Yoshio
AU - Miyama, Akio
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1997/6
Y1 - 1997/6
N2 - A study was conducted into whether or not nicking of the A subunit of Escherichia coil LT enterotoxin at position Arg192 or its neighbouring amino acids Arg192 to The195 is required for its toxicity. The toxic activity of mutants created by substitution or deletion at this position, which lacked ADP-ribosyltransferase activity in vitro, was not completely obliterated and cyclic AMP was partially induced in the target cells, showing that they still displayed enzymic activity in vivo. Moreover, although the A subunit possesses three potential sites for cleavage by furin, furin was not involved in the partial toxicity and cyclic AMP induction observed. These data suggest that target cells have a nick mechanism that operates at sites other than those around Arg192 or those recognized by furin, which generates an active fragment by processing the A subunit after toxin binding to the cell membrane.
AB - A study was conducted into whether or not nicking of the A subunit of Escherichia coil LT enterotoxin at position Arg192 or its neighbouring amino acids Arg192 to The195 is required for its toxicity. The toxic activity of mutants created by substitution or deletion at this position, which lacked ADP-ribosyltransferase activity in vitro, was not completely obliterated and cyclic AMP was partially induced in the target cells, showing that they still displayed enzymic activity in vivo. Moreover, although the A subunit possesses three potential sites for cleavage by furin, furin was not involved in the partial toxicity and cyclic AMP induction observed. These data suggest that target cells have a nick mechanism that operates at sites other than those around Arg192 or those recognized by furin, which generates an active fragment by processing the A subunit after toxin binding to the cell membrane.
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U2 - 10.1099/00221287-143-6-1797
DO - 10.1099/00221287-143-6-1797
M3 - Article
C2 - 9202454
AN - SCOPUS:0030814073
VL - 143
SP - 1797
EP - 1804
JO - Microbiology
JF - Microbiology
SN - 1350-0872
IS - 6
ER -