[[File:EncapsulinIntensity.png|thumb|center|upright=3|DLS measurement of Encapsulin [[parts.igem.org/Part:BBa_K2686002|BBa_K2686002]] using a Zetasizer Nano ZS from Malvern Analytical determining the average particle size using signal intensity. The refractive index chosen for the particles was the "protein" presetting and the refractive index of the medium was approximated to be that of water. This plot shows a peak at 32.674nm]]
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[[File:EncapsulinVolume.png|thumb|center|upright=3|DLS measurement of Encapsulin [[parts.igem.org/Part:BBa_K2686002|BBa_K2686002]] using a Zetasizer Nano ZS from Malvern Analytical determining the average particle size using volumes. The refractive index chosen for the particles was the "protein" presetting and the refractive index of the medium was approximated to be that of water. This plot shows a peak at 21.037nm which corresponds to the encapsulin protein cage within the literature (Putri et al., 2017; Moon et al. 2014).]]
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[[File:EncapsulinCounts.png|thumb|center|upright=3|DLS measurement of Encapsulin [[parts.igem.org/Part:BBa_K2686002|BBa_K2686002]] using a Zetasizer Nano ZS from Malvern Analytical determining the average particle size using the amount of counts. The refractive index chosen for the particles was the "protein" presetting and the refractive index of the medium was approximated to be that of water. This plot shows a peak at 18.166nm]]
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[[File:NegControlVolume.png|thumb|centre|upright=3|Negative control, TX-TL cell free expression medium purified according to the same procedure described above. The refractive index chosen for the particles was the "protein" presetting and the refractive index of the medium was approximated to be that of water.]]
===References===
===References===
Revision as of 07:17, 17 October 2018
Encapsulin protein
This is a BioBrick containing the sequence for Thermotoga maritima encapsulin, a bacterial protein nanocompartment which self assembles to form a 60-mer.
Usage and Biology
Encapsulins are versatile proteins found in a variety of different bacteria (Giessen and Silver, 2017). In the case of this specific part derived from Thermotoga maritima, it can be used among other things to deliver cargo, both on the outer surface of the nanoparticle by fusing a peptide in between the 139/140 Amino Acids or the protein's C terminus. A cargo protein can also be loaded by fusing it with a tag binding to Encapsulin's interior surface (Cassidy-Amstutz et al., 2016).
Sequence and Features
Assembly Compatibility:
10
COMPATIBLE WITH RFC[10]
12
COMPATIBLE WITH RFC[12]
21
INCOMPATIBLE WITH RFC[21]
Illegal BglII site found at 77 Illegal BglII site found at 441
23
COMPATIBLE WITH RFC[23]
25
COMPATIBLE WITH RFC[25]
1000
INCOMPATIBLE WITH RFC[1000]
Illegal SapI.rc site found at 375 Illegal SapI.rc site found at 406
Characterization
A variety of different characterization techniques were used to assess the properties of the encapsulin protein cage.
Expression
A cell free expression system was used to synthesize the encapsulin proteins in vitro. The TX-TL cell free system is a robust way to express proteins (Sun et al., 2013), and was used by last year's EPFL iGEM team Aptasense.
SDS PAGE of encapsulins expressed in cell free TX-TL system with Lysine-BODIPY fluorescent tRNA's (Imager settings used were for measuring fluorescein λex=494nm, λem=512nm ). The two different sets of lanes correspond to different heat denaturation temperatures (70C and 100C for 15 minutes). Stars (✦) show lanes where 60-mers are present. From left to right: (L) Positive control with DNA coding for Luciferase (37kDa), (H) HexaHistidine Encapsulin (BBa_K2686002) showing bands for the encapsulin multimer high on the gel lanes (✦) as well as the monomer around 31kDa, (R) Encapsulin (BBa_K2686001) without HexaHistidine linker also has a band for the 60-mer (✦), (N) Negative control (cell-free TX-TL expression without DNA and 100C denaturation), (Ladder) LC5928 BenchMark™ Fluorescent Protein Standard, (L) Positive control with DNA coding for Luciferase (37kDa), (H) HexaHis Encapsulin (BBa_K2686002) showing bands for the encapsulin multimer high on the gel lanes (✦) as well as the monomer around 31kDa, (R) Encapsulin (BBa_K2686001) without HexaHistidine linker also showing the multimer (✦), (N) Negative control (cell-free TX-TL expression without DNA and 70C denaturation)
References
Cassidy-Amstutz, C., Oltrogge, L., Going, C., Lee, A., Teng, P., Quintanilla, D., East-Seletsky, A., Williams, E. and Savage, D. (2016). Identification of a Minimal Peptide Tag for in Vivo and in Vitro Loading of Encapsulin. Biochemistry, 55(24), pp.3461-3468.
Giessen, T. and Silver, P. (2017). Widespread distribution of encapsulin nanocompartments reveals functional diversity. Nature Microbiology, 2, p.17029.
Putri, R., Allende-Ballestero, C., Luque, D., Klem, R., Rousou, K., Liu, A., Traulsen, C., Rurup, W., Koay, M., Castón, J. and Cornelissen, J. (2017). Structural Characterization of Native and Modified Encapsulins as Nanoplatforms for in Vitro Catalysis and Cellular Uptake. ACS Nano, 11(12), pp.12796-12804.
Shimizu, Y., Inoue, A., Tomari, Y., Suzuki, T., Yokogawa, T., Nishikawa, K. and Ueda, T. (2001). Cell-free translation reconstituted with purified components. Nature Biotechnology, 19(8), pp.751-755.
