ÿþ<!doctype html public "-//w3c//dtd html 3.2//en"> <html> <head> <title>APJMBB Volume 14 Number 2, Dec 2006</title> <meta name="GENERATOR" content="Arachnophilia 4.0"> <meta name="FORMATTER" content="Arachnophilia 4.0"> </head> <STYLE TYPE="text/css"> .head { font-family: Arial narrow, Times new roman, Verdana, Helvetica, sans-serif; font-size: 11pt; color: #000000; font-style: italic;} .title { font-family: Times new roman, Verdana, Arial, Helvetica, sans-serif; font-size: 14pt; color: #000000; font-weight: bold;} .text { font-family: Times new roman, Verdana, Arial, Helvetica, sans-serif; font-size: 12pt; color: #000000;} .affil { font-family: Times new roman, Verdana, Arial, Helvetica, sans-serif; font-size: 11pt; color: #000000; font-style: italic;} .sechead { font-family: Times new roman, Verdana, Arial, Helvetica, sans-serif; font-size: 12pt; color: #000000; font-weight: bold;} A {text-decoration:none} A:hover {color:#ff8040;} .text3 { font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 9pt; color: #000000;} .text4 { font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 9pt; color: #0000ff;} .text2 { font-family: Times new roman, Verdana, Arial, Helvetica, sans-serif; font-size: 9pt; color: #000000;} </STYLE> <body bgcolor="#ffffff" text="#000000" link="#0000ff" vlink="#800080" alink="#ff0000"> <img src="../images/apjlogos.gif" width="125" height="87" alt=""><br><hr width=90% align=left> <span class=text3><a href="142cont.htm">[ Contents ]</a> <a href="142a.htm">[ Previous abstract ]</a> <a href="142c.htm">[ Next abstract ]</a> <a href="../html141/141cont.htm">[ Previous issue ]</a> [ Next issue ] <a href="../../apjhome.htm">[ APJMBB home ]</a></span><hr width=90% align=left> <p class=head>As. Pac. J. Mol. Biol. &amp; Biotech., Dec 2006 Vol. 14, 41-45</p> <table width="90%" border="0" cellspacing="0" cellpadding="5"> <tr> <td width=100% valign=top><span class=title>The Periplasmic Expression of Recombinant Human Epidermal Growth Factor (hEGF) in <i>Escherichia coli</i> </span><br> <br> <span class=text>Ahmad Faizal Abdull Razis<sup>1</sup>, Elysha Nur Ismail<sup>1</sup>, Zarida Hambali<sup>2</sup>, Muhammad Nazrul Hakim Abdullah<sup>2</sup>, Abdul Manaf Ali<sup>3</sup>, Mohd Azmi Mohd Lila<sup>4</sup></span><br> <br> <span class=affil><sup>1</sup>Laboratory of Immunotherapeutic and Vaccines, Institute of Bioscience, UPM<br> <sup>2</sup>Faculty of Medicine and Health Sciences, UPM<br> <sup>3</sup>Faculty of Biotechnology and Biomolecular Sciences, UPM<br> <sup>4</sup>Faculty of Veterinary Medicine, UPM</span> <p class=text2><sup>*</sup>Author for Correspondence.<br> Laboratory of Immunotherapeutic and Vaccines,<br> Institute of Bioscience, 43400<br> Universiti Putra Malaysia<br>Serdang, Selangor MALAYSIA<br>Tel:+603-89464194/+6017-3484844<br>Email: ahmadfaizal2003@yahoo.com </p> <p class=text align=justify><span class=sechead>Abstract.</span><br> Expression of recombinant eukaryotic proteins in <i>Escherichia coli</i> often results in the formation of inclusion bodies. In the case of disulfide-bonded proteins such as hEGF, inclusion body formation can be anticipated if the protein is produced in the bacterial cytosol. The consequence is improper folding which results in aggregation. Proper folding and solubility of such protein are pre-requisite for its biological activity. This is not achieved in cytoplasmic expression in E. coli because of the absence of disulfide bonds formation. The human epidermal growth factor (<i>hEGF</i>) gene has been cloned into the pFLAG fusion protein expression vector. The expression system used OmpA signal sequence to translocate processed and soluble proteins into the periplasm of <i>E. coli</i> cells. Molecular weight of secreted hEGF into periplasmic space was found approximately 6.8 kDa, similar size to the original protein which confirmed by SDS-PAGE and western blotting analysis. The findings obtained, showed in favor of periplasmic expression system, which may be suitable to produce the small eukaryotic disulfide-bonded proteins like hEGF.</p> <a href="1424145.pdf" class=text4>[Get pdf]</a> </td></tr></table> <br> <br> <br> <br> </body> </html>