In Silico Evaluation of Different Signal Peptides for the Secretory Production of Human Growth Hormone in E. coli

Abstract

Various advantages of protein secretion have prompted scientists to search for secretory production of heterologous proteins. Signal peptides are one of the most important factors for prosperous secretion of the recombinant proteins. The aim of this study was to evaluate 23 different signal peptides and theoretically determine suitable ones for secretory production of the human growth hormone (hGH) in the E. coli host. The signal peptide sequences and the precise location of their cleavage sites were predicted using SignalP 4.0 server. Accordingly, six of the signal peptides, including hGH, major outer membrane lipoprotein, protease VII, protein TolB, periplasmic protein TorT and beta-lactamase TEM were excluded from the further study, due to their inappropriate cleavage scores. Different physico-chemical properties, which are essential for selecting a proper signal peptide, were evaluated using ProtParam and Solpro as the most accurate and reliable servers. Computational analysis of the abovementioned factors, indicates that outer membrane protein C, fimbrial chaperone SfmC, outer membrane protein F and disulfide interchange protein DsbA can theoretically be suitable signal peptides for hGH secretion.

Expression and rapid purification of recombinant biologically active ovine growth hormone with DsbA targeting to Escherichia coli inner membrane

“…Similarly, the secretion of the human GH to the periplasm has been reported earlier (Soares et al 2003;Becker and Hsiung 1986) using DsbA signal sequence. Moreover, the theoretical analysis of 22 different signal peptides by using bioinformatics tools also proved DsbA as the best signal sequence for the soluble expression of human GH (Zamani et al 2015).…”

“…The information about primary and secondary structure of target protein also affects its translocation (Zamani et al 2015) as in GH because it is highly hydrophobic and possesses alpha helical structures that resemble helical bundle class of inner membrane proteins (IMPs). It is known that DsbA is an SRP signal sequence (Schierle et al 2003) and SRP pathway is primarily used by E. coli for targeting the IMPs.…”

Twin arginine translocation system in secretory expression of recombinant human growth hormone

“…OmpA, STII, penicillinase, PhoA, LTB, NPR, DsbA, pelB, and natural hGH signal peptide were used in the different study to enhance the secretory expression of somatropin in E. coli (92829). In this regard, Zamani et al .…”

“…In this regard, Zamani et al . has predicted the effect of different signal sequences on the efficiency of the system by in silico methods (29). However their ranking is not approved by the in vitro studies.…”

In Silico B Cell and T Cell Epitopes Evaluation of lipL32 and OmpL1 Proteins for Designing a Recombinant Multi-Epitope Vaccine Against Leptospirosis

“…In this study, the most accurate and reliable bioinformatics tools were applied to predict B cell and T cell epitopes of ompL1 and LipL32 (18)(19)(20). As our result showed, 20 to 25 amino acids, at the beginning of both proteins, cannot be epitopes because these amino acid sequences are usually considered as a signal peptide to translocate proteins to the endoplasmic reticulum and they are then cleaved by signal peptidase (27,28). Therefore, these amino acid sequences cannot be exposed as epitopes on the surface of the bacteria to stimulate the immune system.…”