Identification of a novel M-superfamily conotoxin with the ability to enhance tetrodotoxin sensitive sodium currents.
In this work, a novel M-superfamily conotoxin, designated lt3a, was purified from the crude venom of Conus litteratus. Combined with peptide sequencing, MALDI-TOF mass spectrometry and cDNA cloning techniques, the amino acid sequence of lt3a was supposed to be DgammaCCgamma OQWCDGACDCCS, where O is hydroxyproline and gamma is carboxyglutamate. The Cys framework of lt3a (-CC-C-C-CC-) is similar to that of psi-, mu-, kappaM-conotoxins, which are representatives of M-conotoxins. Peptide lt3a is categorized into M1 branch based on the number of residues in the last Cys loop. Whole cell patch-clamp study on adult rat dorsal root ganglion neurons indicated that lt3a could enhance tetrodotoxin-sensitive sodium currents. This is a previously unknown function of M-superfamily conotoxins.
Wang
Lei
L
State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, Department of Biochemistry, College of Life Sciences, Sun Yat-sen (Zhongshan) University, 135 Xingangxi Road, 510275 Guangzhou, People's Republic of China.
Liu
Junliang
J
Pi
Canhui
C
Zeng
Xiayun
X
Zhou
Maojun
M
Jiang
Xiaoyu
X
Chen
Shangwu
S
Ren
Zhenghua
Z
Xu
Anlong
A
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D020916:Conotoxins / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity*; D052078:Conus Snail / Q000378:metabolism; D004553:Electric Conductivity; D020224:Expressed Sequence Tags / Q000737:chemistry; D005727:Ganglia, Spinal / Q000187:drug effects / Q000502:physiology; D008969:Molecular Sequence Data; D051381:Rats; D017207:Rats, Sprague-Dawley; D015222:Sodium Channels / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013779:Tetrodotoxin / Q000494:pharmacology
D020916:Conotoxins; D015222:Sodium Channels; C544866:lt3a conotoxin, Conus litteratus; D013779:Tetrodotoxin