Expression, Purification and

Expression,
Purification and Characterization of Human Prorelaxin-like-protein H2 in Escherichia
coli

CHEN Li-Ming, YANG Xing-Wen, TANG
Jian-Guo^*

( National Laboratory of Protein
Engineering and Plant Genetic Engineering, Peking University, Beijing 100871,
China )

Abstract    The cDNA
gene encoding human prorelaxin H2 was subcloned from plasmid pMAL p2X-hRLX H2
into the EcoRI and BamHI sites of prokaryotic
expression vector pBV220, resulting in the recombinant plasmid pBV220-hPRLX H2,
which was subsequently transformed into Escherichia coli
DH5&arg;. The target gene was highly expressed in the form of inclusion
body by thermoinduction at 42 ℃. Recombinant human Met-prorelaxin-like-protein
H2 was refolded in vitro, purified by Sephadex G-75 gel
filtration chromatography and reverse phase fast protein liquid chromatography.
The yield was approximately 2-3 mg/L. The purified recombinant human
Met-prorelaxin-like-protein H2 was shown to be a single band by 15% SDS-PAGE
and gave correct amino acid composition of Met-prorelaxin. Molecular weight of
the purified recombinant human Met-prorelaxin-like-protein H2 was measured to
be 18 390.4 (calculated theoretical value 18 392.3) by matrix assisted laser
desorption ionization time-of-flight mass spectroscopy.
Key words    human prorelaxin-like-protein; expression;
protein purification; genetic engineering

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Fax, 86-10-62751526; e-mail, [email protected]