Low density lipoprotein inactivates Vibrio vulnificus cytolysin through the oligomerization of toxin monomer.
Blood lipoprotein has been shown to be an important defense factor against the bacterial infection. Lipoprotein is scavenger of bacterial endotoxin (lipopolysaccharide, LPS). However, there is little evidence showing its protective action against the bacterial exotoxin. We have previously demonstrated that cholesterol inactivates Vibrio vulnificus cytolysin (VVC) through oligomerization of the toxin monomer. The aim of the present study was to investigate the relationship between VVC and low-density lipoprotein cholesterol (LDL-C). LDL induced the oligomerization of VVC in a dose-dependent manner. The oligomerization of VVC monomer with LDL was demonstrated by immunoblotting, which exhibited 200-kDa bands corresponding to a tetramer of the native VVC of relative molecular weight of 51,000. Moreover, LDL inactivated hemolytic activity of VVC in a dose-dependent manner, and this response was not changed by the modifications of LDL (heat denaturation of proteins and peroxidation of phospholipids), suggesting that LDL-C is associated with the defense action against VVC. These results suggest that LDL-C inactivates VVC through the induction of toxin oligomerization.
Park
Kwang-Hyun
KH
Department of Biochemistry, Chonbuk National University Medical School, 560-182, Chonju, South Korea.
Yang
Haet-Bit
HB
Kim
Hyung-Gue
HG
Lee
Young-Rae
YR
Hur
Hyoun
H
Kim
Jong-Soo
JS
Koo
Bon-Sun
BS
Han
Myung-Kwan
MK
Kim
Jong-Hyun
JH
Jeong
Young-Ju
YJ
Kim
Jong-Suk
JS
D000818:Animals; D001426:Bacterial Proteins; D001427:Bacterial Toxins / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D008078:Cholesterol, LDL / Q000494:pharmacology / Q000502:physiology*; D006460:Hemolysin Proteins / Q000737:chemistry*; D006461:Hemolysis; D015151:Immunoblotting; D015227:Lipid Peroxidation; D051379:Mice; D008970:Molecular Weight; D011489:Protein Denaturation; D041261:Vibrio vulnificus
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D008078:Cholesterol, LDL; D006460:Hemolysin Proteins; C073845:hemolysin, Vibrio