Inactivation of Vibrio vulnificus hemolysin by oligomerization but not proteolysis.
Vibrio vulnificus extracellular protease (VvpE) is believed to destroy its hemolysin (VvhA) in the late growth phase, without obvious experimental evidence. So, we attempted to elucidate the mechanism. The hemolytic activity steeply increased with the expression of the VvhA in the early growth phase, and then abruptly declined with the expression of VvpE in the late growth phase. However, the VvhA activity also abruptly declined in a VvpE-deficient mutant. In Western blot, the degradation of VvhA was not observed; instead, the oligomerization of VvhA increased with the concomitant loss of hemolytic activity. These results evidently indicate that the inactivation of VvhA is due to the novel oligomerization of VvhA by unknown mechanism, but not to the destruction of VvhA by VvpE, so that the routine functional assay measuring hemolytic activity cannot reflect the actual production of VvhA.
Research Center for Resistant Cells, Chosun University Medical School, Gwangju, South Korea. shsin@chosun.ac.kr
Sung-Heui
SH
Shin
Hui-Yu
HY
Sun
Mi-Hwa
MH
Choi
Ra-Young
RY
Park
Young-Hoon
YH
Bai
Choon-Mee
CM
Kim
Soo-Young
SY
Kim
Young-Ran
YR
Kim
Shee-Eun
SE
Lee
Joon-Haeng
JH
Rhee
D001704:Biopolymers; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D006460:Hemolysin Proteins; D006868:Hydrolysis; D010447:Peptide Hydrolases / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D041261:Vibrio vulnificus / Q000378:metabolism*
D001704:Biopolymers; D006460:Hemolysin Proteins; D010447:Peptide Hydrolases