Cloning and Optimized
Expression of Human Angiogenin in E. coli
LU Fan, YANG Hui, ZHAO Zhong-Liang*, CHEN
Nan-Chun and CHEN Su-Min
( Department of Biochemistry and Molecular Biology, Fourth Military Medical
University, Xi’an 710032, China )
Abstract
ANGiogenin(ANG) is an important factor of angiogenesis during different stage
of tumor development and exists widely in various tumors. To study the
biological funcption and find the antagonistic drugs of angiogenin, the
angiogenin was allowed to be expressed by E.coli. By the aid of
computer,the sequence around the start codon of angiogenin gene was modified
according to local secondary structure. The modified human ang gene
was amplified by reverse-transcription polymerase chain reaction from the human
lung cancer cell line A549, and inserted into the prokaryotic expression vector
pLDH99. After screening, high expression recombinants were obtained, and the
expression level of the hANG was about 30% of total bacteria protein by SDS-PAGE.
Biological assays indicated that the rhANG could induce new blood vessel
formation in CAM in vitro. Our data showed that the recombinant hANG
was active and the optimized expression of ang gene was practicable.
Key words angiogenin；RT-PCR；recombinant DNA
*Corresponding author：Tel, 86-29-3374516-16；e-mail,[email protected]