Aspen SP1, an exceptional thermal, protease and detergent-resistant self-assembled nano-particle.
Stable protein 1 (SP1) is a homo-oligomeric protein isolated from aspen (Populus tremula aspen) plants which forms a ring-shape dodecameric particle with a central cavity. The oligomeric form of SP1 is an exceptionally stable structure that is resistant to proteases (e.g., trypsin, V8, and proteinase K), high temperatures, organic solvents, and high levels of ionic detergent. Analytical ultra-centrifugation, chemical cross-linking, matrix-assisted laser-desorption time-of-flight mass spectrometry (MALDI-TOF-MS), and transmission electron microscopy were used to further characterize the SP1 dodecamer. Introduction of a single cysteine at the N-terminus of SP1 enabled the formation of disulfide bridges within the SP1 dodecamer, concurrent with increased melting point. A six-histidine tag was introduced at the N-terminus of SP1 to generate 6HSP1, and the DeltaNSP1 mutant was generated by a deletion of amino acids 2-6 at the N-terminus. Both 6HSP1 and DeltaNSP1 maintained their ability to assemble a stable dodecamer. Remarkably, these SP1 homo-dodecamers were able to re-assemble into stable hetero-dodecamers following co-electro-elution from SDS-PAGE. The exceptional stability of the SP1-nano ring and its ability to self-assemble hetero-complexes paves the way to further research in utilizing this unique protein in nano-biotechnology.
Wang
Wang-Xia
WX
The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, and the Otto Warburg Center for Agricultural Biotechnology, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Israel.
Dgany
Or
O
Wolf
Sharon Grayer
SG
Levy
Ilan
I
Algom
Rachel
R
Pouny
Yehonathan
Y
Wolf
Amnon
A
Marton
Ira
I
Altman
Arie
A
Shoseyov
Oded
O
D003460:Crystallization / Q000379:methods*; D003902:Detergents / Q000737:chemistry*; D019281:Dimerization; D004789:Enzyme Activation; D004795:Enzyme Stability; D046912:Multiprotein Complexes / Q000032:analysis / Q000737:chemistry / Q000648:ultrastructure; D049329:Nanostructures / Q000032:analysis / Q000737:chemistry* / Q000648:ultrastructure*; D010940:Plant Proteins / Q000032:analysis / Q000737:chemistry* / Q000648:ultrastructure*; D032107:Populus / Q000201:enzymology*; D011485:Protein Binding; D013696:Temperature
D003902:Detergents; D046912:Multiprotein Complexes; D010940:Plant Proteins