coli (DH5α) competent cells by standard protocols. On average two recombined DNA clones for each amplified fragment were bidirectionally sequenced by the

Beijing Genomics Institute (BGI, Beijing, China). Sequence alignments were based on multiple alignments provided by the software Clustal W version 1.8 (http://www.clustal.org/), Ultraedit 3.2 (http://www.ultraedit.com/) and Bioedit 7.0 (http://www.mbio.ncsu.edu/BioEdit). A neighbor-joining tree of the genes cloned in this study and other selleck chemical genes in GenBank was constructed based upon the deduced amino acid sequences without signal peptides using Mega 4.0. The identification of the four major immunogenic peptides in α-gliadins and their chromosomal locations followed Van Herpen et al. [13]. Prediction of the secondary structure of α-gliadins was performed with the latest online version (3.3) of the PSIPRED server (http://bioinf.cs.ucl.ac.uk/psipred/psiform.html). The positive recombinant pMD-19T-α-gliadin plasmids and pET30a plasmids were digested Selleckchem Ivacaftor with the

enzymes Hind III and BamH I (FastDigest enzyme, Fermentas, Canada) at 37 °C for 20 min and the target fragments were purified and ligated together with the fast ligation kit of Sangon Biotech (Shanghai, China). The identity of the recombinant pET30a-α-gliadin plasmids was confirmed by PCR and DNA bidirectional sequencing (BGI, Beijing, China) and the positive recombinant plasmids were transformed into E. coli BL21 (DE3) (Novagen) competent cells. The fusion protein was induced by 1 mmol L− 1 IPTG at 37 °C for at least 4 h. Fusion protein was extracted from the bacteria using the method

described by Xu et al. [26], with some modifications. SDS-PAGE electrophoresis and Western blotting were referred to the method described by Li et al. [10]. A total almost of 43 unique clones, designated as Z4A-1 to Z4A-43, were isolated from common wheat cultivar Zhengmai 004 by a genomic PCR-based strategy. Among them, 22 clones (Z4A-1 to Z4A-22) were full-ORF genes that could encode protein subunits with the size of 286–312 amino acid residues. NCBI BLAST searches of their entire nucleotide sequences showed that 42 sequences had a high degree (84%–99%) of identity with the typical α-gliadin sequences in GenBank, with the exception of the complete identity of Z4A-22 with the previously submitted sequence (JX828270) that we isolated earlier from common wheat cultivar Zhengmai 9023.