Enhanced stability of heterologous proteins by supramolecular self-assembly.
Recently, we reported on the dual function of human ferritin heavy chain (hFTN-H) used for the fusion expression and solubility enhancement of various heterologous proteins: (1) high-affinity interaction with HSP70 chaperone DnaK and (2) formation of self-assembled supramolecules with limited and constant sizes. Especially the latter, the self-assembly function of hFTN-H is highly useful in avoiding the undesirable formation of insoluble macroaggregates of heterologous proteins in bacterial cytoplasm. In this study, using enhanced green fluorescent protein (eGFP) and several deletion mutants of Mycoplasma arginine deiminase (ADI(132-410)) as reporter proteins, we confirmed through TEM image analysis that the recombinant fusion proteins (hFTN-H::eGFP and hFTN-H::ADI(132-410)) formed intracellular spherical particles with nanoscale diameter ( approximately 10 nm), i.e., noncovalently cross-linked supramolecules. Surprisingly, the supramolecular eGFP and ADI showed much enhanced stability in bioactivity. That is, the activity level was much more stably maintained for the prolonged period of time even at high temperature, at high concentration of Gdn-HCl, and in wide range of pH. The stability enhancement by supramolecular self-assembly may make it possible to utilize the protein supramolecules as novel means for drug delivery, enzymatic material conversion (biotransformation), protein chip/sensor, etc. where the maintenance of protein/enzyme stability is strictly required.
Park
Jin-Seung
JS
Department of Chemical and Biological Engineering, College of Engineering, Korea University, Seoul, 136-713, South Korea.
Ahn
Ji-Young
JY
Lee
Sung-Hyun
SH
Lee
Hyewon
H
Han
Kyung-Yeon
KY
Seo
Hyuk-Seong
HS
Ahn
Keum-Young
KY
Min
Bon Hong
BH
Sim
Sang Jun
SJ
Choi
Insung S
IS
Kim
Yang Hoon
YH
Lee
Jeewon
J
D001709:Biotechnology / Q000379:methods; D005293:Ferritins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D049452:Green Fluorescent Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D006867:Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D009174:Mycoplasma / Q000201:enzymology* / Q000235:genetics; D053758:Nanoparticles / Q000737:chemistry*; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D011993:Recombinant Fusion Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D005293:Ferritins; D006867:Hydrolases; C019723:arginine deiminase