Purification and characterization of curcin, a toxic lectin from the seed of Jatropha curcas.
The seed of the plant Jatropha curcas contains a toxic protein, designated as curcin, which was purified to apparent homogeneity by the combined use of chromatography on Sephdex G-100. The molecular weight of 28.2 kDa and the pI of 8.54 were determined. The protein was found to be a glycoprotein; the total neutral-surge content was 4.91%. It strongly inhibits the protein synthesis of rabbit reticulocyte lysate, with an IC(50) of 0.42 nM. It was determined by Edman that the sequence of the N-terminal thirty-two amino acids was: A-G/Y-S/K-T/A-P/D-T-L-T-I-T-Y-D-A-T/A-A-D-K-K-N-Y-A-Q-F-I-K-D-L-R-E-A-F/A-G. The isolated curcin had a hemagglutinating activity, when its concentration was more than 7.8 mg/L. The secondary structure of curcin was analyzed by Circular Dichroism (CD) spectrum. The result shows the curcin contains alpha-helix (22.3%), beta-sheet (43.5%), and random coil and corner (34.2%). The results of acute toxicity in mice show that mice oral semi-lethal dose LD(50) was 104.737 +/- 29.447 mg/kg; mice parenteral semi-lethal dose LD(50) was 67.20 +/- 10.445 mg/kg.
Lin
Juan
J
State Key Laboratory of Genetic Engineering, School of Life Sciences, Morgan-Tan International Center for Life Sciences, Fudan University, Shanghai, P R China. linjuan@fudan.edu.cn
Zhou
Xin
X
Wang
Jinya
J
Jiang
Peihong
P
Tang
Kexuan
K
D000818:Animals; D004305:Dose-Response Relationship, Drug; D007928:Lethal Dose 50; D008297:Male; D051379:Mice; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity*; D054789:Ribosome Inactivating Proteins, Type 1 / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity*; D012639:Seeds / Q000737:chemistry*; D015996:Survival Rate; D018675:Toxicity Tests
D010936:Plant Extracts; D054789:Ribosome Inactivating Proteins, Type 1; C515388:curcin protein, Jatropha curcas