2. Materials and methods
2.1. Plasmid construction
Plasmids were constructed using standard recombinant technique
[14]. The codon-optimized GLP-1 analogue gene was synthesized by
PCR based on the designed sequence using long sense and antisense
oligonucleotides with overlaps of 18 nt as primers using high fidelity
Taq polymerase. This GLP-1 analogue gene was introduced between
amino acid positions 109 and 110 of 26 kDa globulin cDNA by two-
overlap extension PCR method, and then fused to 980 bp globulin
promoter. The EcoRI–Sse8387I fragment of Glb promoter-globulin
(GLP-1 analogue)-Nos terminator was ligated into the EcoRI–
Sse8387I site of pTL7 to produce pGlbGLP. The KpnI fragment of
the CaMV35S promoter-hph-Nos terminator was ligated into the inter-
nal KpnI site of the R/RS cassette of pNPI130PUC to produce
pNPI130Hm [12]. The Sse8387I fragment of pNPI130Hm was cloned
into the Sse8387I site of pGlbGLP to produce pGlbGLP130Hm.
2.2. Transformation
This pGlbGLP130Hm was introduced into Agrobacterium tumefac-
iens strain EHA105 by electroporation [15].
Corresponding author. Fax: +81 29 838 8397.
E-mail address: takaiwa@nias.affrc.go.jp (F. Takaiwa).
1
*
These authors contributed equally to the paper.
0014-5793/$30.00 Ó 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
doi:10.1016/j.febslet.2004.12.082