%0 Journal Article
%T Expression and purification of hepatitis B surface antigen S from Escherichia coli; a new simple method
%A Mohamed S Elghanam
%A Ahmed S Attia
%A Hussein A Shoeb
%A Abd Elgawad M Hashem
%J BMC Research Notes
%D 2012
%I BioMed Central
%R 10.1186/1756-0500-5-125
%X To achieve this goal, the gene encoding the HBsAg(S) protein was cloned and expressed as a fusion protein with a GST tag in Escherichia coli. The recombinant protein was successfully expressed and purified in both good quality and quantity.The simplified and the relatively low cost of the used protocol make this an attractive alternative to protocols currently used for the purification of HBsAg(S). The exploiting of this achievement for new diagnostics can be directed for application in the developing countries where they are extremely needed.Hepatitis B disease is a widely spread disease; it is estimated that approximately 2 billion people (one third of the world's population) have serological evidence of past or present HBV infection, and more than 350 million people are chronically infected [1]. It is highly endemic in developing regions with large population such as South East Asia, China, Sub-Saharan Africa and the Amazon basin, where at least 8% of the population are HBV chronic carriers [2].The env gene of HBV codes for three related proteins: (1) S protein (HBsAg(S)), a 226 amino acids protein identified as a major protein constituent of the HBV envelope; (2) a 'middle' protein carrying 55 amino acids at the N-terminus encoded by the pre-S2 portion of the pre-S region; (3) and a 'large' protein encoded by the whole ORF (pre-S1, pre-S2 and S, 389aa). The latter 2 proteins represent the minor component of HBV envelop [3,4]. Among the three proteins, HBsAg(S) has the highest density of epitopes against HBsAb [5].HBsAg has been used for a long time as a vaccine candidate and as a diagnostic immunoassay component. In early 1980s, plasma collected from chronic HBsAg carriers was used as a source of HBsAg. However, this came with bio safety concerns and required rigorous heat or chemical inactivation processes. However upon the development of recombinant DNA techniques HBsAg was expressed and purified in different systems both eukaryotic and prokaryotic one [6].The
%K Hepatitis B
%K HBsAg
%K Purification
%K GST-fusion
%U http://www.biomedcentral.com/1756-0500/5/125