Revision as of 15:10, 7 December 2017

T7 Promoter+RBS+Sa-AFP2

Figure 1. P_T7+RBS+Sa-AFP2+terminator

Introduction

      This peptide possesses antifungal activity sensitive to inorganic cations from the defensin family and was proved to have an anti-fungal function [1]. NCTU_Formosa used it to be one of a training data for forming the antifungal peptide scoring card.

Experiment

1. Cloning

      We put T7 promoter, RBS, and Sa-AFP2 together with pSB1C3 as a backbone. Then we conducted Taq PCR to check the size of the DNA sequence was right. The length of T7 promoter+RBS+Sa-AFP2 is around 234 b.p. Its PCR product is around 546 b.p.

Figure 2. P_T7 + RBS + Sa-AFP2
The DNA sequence length of P_T7 + RBS + Sa-AFP2 is around 200 ~ 250 b.p. The size of its PCR product should be close to 500 ~ 550 b.p.

2. Expressing

      Because Sa-AFP2 had not been expressed by E. coli before, it was a new challenge. The strain we chose to make Sa-AFP2 was E. coli Rosetta-gami strain, which forms the disulfide bonds in the cytoplasm to express the protein. To ensure the peptide was produced, after breaking the bacteria and boiling the lysate with sample buffer and β-mercaptoethanol mixture for 15 minutes, we run SDS-PAGE to check the mass of the peptide. The mass of Sa-AFP2 is around 5.6 kDa.

Figure 3.The mass of Sa-AFP2 is around 5.7 kDa. The result shows that NO.2, No.3, No.5, and No.6 had made the peptide.

Safety

      We do the safety part which is the same as the Sa-AFP1. See more in BBa_K2262005.

Reference

[1] Terras FR1; Torrekens S; Van Leuven F; Osborn RW; Vanderleyden J; Cammue BP; Broekaert WF. "A new family of basic cysteine-rich plant antifungal proteins from Brassicaceae species." FEBS Lett. 1993 Feb 1;316(3):233-40.

Sequence and Features