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ISSN 0582-9879 Acta Biochim et Biophysica Sinica 2004, 36(4):297-332 CN 31-1300/Q

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Purification of a Novel Antibacterial Short Peptide in Earthworm Eisenia foetida

Yan-Qin LIU^1,2, Zhen-Jun SUN¹*, Chong WANG¹, Shi-Jie LI², and Yu-Zhi LIU²
( ¹ College of Resource and Environment Science, China Agricultural University, Beijing 100094, China;
² College of Animal Science, Hebei Agricultural University, Baoding 071001, China )

Abstract A novel antimicrobial short peptide was purified from earthworm (Eisenia foetida) by a five-step protocol including ammonium sulfate precipitation, ultrafiltration, DE-52 ion exchange chromatography, Sephadex G-10 column chromatography, and C-18 reversed-phase HPLC techniques. The purified peptide was applied to the MALDI-TOF MS to determine the molecular mass and was also subjected to TOF MS-MS analysis to determine the amino acid sequence. As a result, a novel antibacterial peptide, named OEP3121, was obtained, with the molecular mass of 510.8 Da and the sequence being "ACSAG".

Key words antibacterial peptide; earthworm; purification

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Received: November 24, 2003 Accepted: February 12, 2004
This work was supported by the grants from the National Natural Science Foundation of China (No. 30270195) and the Doctorial Foundation of National Education Committee of China (20020019029)
*Corresponding author: Tel, 86-10-62892942; Fax, 86-10-62892498; Email, sun108@cau.edu.cn