Guest-protein incorporation into solvent channels of a protein host crystal (hostal)
(2021) In Acta Crystallographica Section D: Structural Biology 77. p.471-485- Abstract
Soaking small molecules into the solvent channels of protein crystals is the most common method of obtaining crystalline complexes with ligands such as substrates or inhibitors. The solvent channels of some protein crystals are large enough to allow the incorporation of macromolecules, but soaking of protein guests into protein crystals has not been reported. Such protein host crystals (here given the name hostals) incorporating guest proteins may be useful for a wide range of applications in biotechnology, for example as cargo systems or for diffraction studies analogous to the crystal sponge method. The present study takes advantage of crystals of the Escherichia coli tryptophan repressor protein (ds-TrpR) that are extensively... (More)
Soaking small molecules into the solvent channels of protein crystals is the most common method of obtaining crystalline complexes with ligands such as substrates or inhibitors. The solvent channels of some protein crystals are large enough to allow the incorporation of macromolecules, but soaking of protein guests into protein crystals has not been reported. Such protein host crystals (here given the name hostals) incorporating guest proteins may be useful for a wide range of applications in biotechnology, for example as cargo systems or for diffraction studies analogous to the crystal sponge method. The present study takes advantage of crystals of the Escherichia coli tryptophan repressor protein (ds-TrpR) that are extensively domain-swapped and suitable for incorporating guest proteins by diffusion, as they are robust and have large solvent channels. Confocal fluorescence microscopy is used to follow the migration of cytochrome c and fluorophore-labeled calmodulin into the solvent channels of ds-TrpR crystals. The guest proteins become uniformly distributed in the crystal within weeks and enriched within the solvent channels. X-ray diffraction studies on host crystals with high concentrations of incorporated guests demonstrate that diffraction limits of ∼2.5 Å can still be achieved. Weak electron density is observed in the solvent channels, but the guest-protein structures could not be determined by conventional crystallographic methods. Additional approaches that increase the ordering of guests in the host crystal are discussed that may support protein structure determination using the hostal system in the future. This host system may also be useful for biotechnological applications where crystallographic order of the guest is not required.
(Less)
- author
- Sprenger, Janina LU ; Carey, Jannette LU ; Schulz, Alexander ; Drouard, Fleur ; Lawson, Catherine L. ; Von Wachenfeldt, Claes LU ; Linse, Sara LU and Leggio, Leila Lo
- organization
- publishing date
- 2021
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- diffusion, encapsulation, host-guest system, hostals, mesopores, MOLEonline, protein volume fraction, solvent channels
- in
- Acta Crystallographica Section D: Structural Biology
- volume
- 77
- pages
- 15 pages
- publisher
- John Wiley & Sons Inc.
- external identifiers
-
- scopus:85103982964
- pmid:33825708
- ISSN
- 2059-7983
- DOI
- 10.1107/S2059798321001078
- language
- English
- LU publication?
- yes
- id
- b2d76270-3dda-4718-a69f-f057e8e22397
- date added to LUP
- 2021-04-21 07:04:57
- date last changed
- 2024-11-17 02:58:10
@article{b2d76270-3dda-4718-a69f-f057e8e22397,
abstract = {{<p>Soaking small molecules into the solvent channels of protein crystals is the most common method of obtaining crystalline complexes with ligands such as substrates or inhibitors. The solvent channels of some protein crystals are large enough to allow the incorporation of macromolecules, but soaking of protein guests into protein crystals has not been reported. Such protein host crystals (here given the name hostals) incorporating guest proteins may be useful for a wide range of applications in biotechnology, for example as cargo systems or for diffraction studies analogous to the crystal sponge method. The present study takes advantage of crystals of the Escherichia coli tryptophan repressor protein (ds-TrpR) that are extensively domain-swapped and suitable for incorporating guest proteins by diffusion, as they are robust and have large solvent channels. Confocal fluorescence microscopy is used to follow the migration of cytochrome c and fluorophore-labeled calmodulin into the solvent channels of ds-TrpR crystals. The guest proteins become uniformly distributed in the crystal within weeks and enriched within the solvent channels. X-ray diffraction studies on host crystals with high concentrations of incorporated guests demonstrate that diffraction limits of ∼2.5 Å can still be achieved. Weak electron density is observed in the solvent channels, but the guest-protein structures could not be determined by conventional crystallographic methods. Additional approaches that increase the ordering of guests in the host crystal are discussed that may support protein structure determination using the hostal system in the future. This host system may also be useful for biotechnological applications where crystallographic order of the guest is not required.</p>}},
author = {{Sprenger, Janina and Carey, Jannette and Schulz, Alexander and Drouard, Fleur and Lawson, Catherine L. and Von Wachenfeldt, Claes and Linse, Sara and Leggio, Leila Lo}},
issn = {{2059-7983}},
keywords = {{diffusion; encapsulation; host-guest system; hostals; mesopores; MOLEonline; protein volume fraction; solvent channels}},
language = {{eng}},
pages = {{471--485}},
publisher = {{John Wiley & Sons Inc.}},
series = {{Acta Crystallographica Section D: Structural Biology}},
title = {{Guest-protein incorporation into solvent channels of a protein host crystal (hostal)}},
url = {{http://dx.doi.org/10.1107/S2059798321001078}},
doi = {{10.1107/S2059798321001078}},
volume = {{77}},
year = {{2021}},
}