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Crowning proteins: modulating the protein surface properties using crown ethers.

Lee CC, Maestre-Reyna M, Hsu KC, Wang HC, Liu CI, Jeng WY, Lin LL, Wood R, Chou CC, Yang JM, Wang AH - Angew. Chem. Int. Ed. Engl. (2014)

Bottom Line: We elucidated the crystal structures of several protein-crown ether co-crystals grown in the presence of 18-crown-6.We then employed biophysical methods and molecular dynamics simulations to compare these complexes with the corresponding apoproteins and with similar complexes with ring-shaped low-molecular-weight polyethylene glycols.Consequently, we propose that crown ethers can be used to modulate a wide variety of protein surface behaviors, such as oligomerization, domain-domain interactions, stabilization in organic solvents, and crystallization.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biological Chemistry, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529 (Taiwan); Core Facilities for Protein Structural Analysis, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529 (Taiwan).

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18-Crown-6 binding modes. The upper part of each panel illustrates the structure of the molecule, the lower part is a representation, where dashed lines represent hydrogen bonds and the red semi-circles are hydrophobic contacts. a) In the K-crown binding mode, a single lysine binds the CR axially. b) Hydrophobic and π-orbital containing side-chains interact laterally with CR. No residues interact with the central region of CR, which commonly but not always coordinates two water molecules. Letters in parenthesis indicate the chain ID. c) In the mixed KC-crown binding mode, the CR is coordinated axially by a lysine, while hydrophobic and π-orbital containing side-chains interact with it laterally. Letters in parenthesis indicate the chain ID, with asterisk indicating symmetry equivalents.
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fig03: 18-Crown-6 binding modes. The upper part of each panel illustrates the structure of the molecule, the lower part is a representation, where dashed lines represent hydrogen bonds and the red semi-circles are hydrophobic contacts. a) In the K-crown binding mode, a single lysine binds the CR axially. b) Hydrophobic and π-orbital containing side-chains interact laterally with CR. No residues interact with the central region of CR, which commonly but not always coordinates two water molecules. Letters in parenthesis indicate the chain ID. c) In the mixed KC-crown binding mode, the CR is coordinated axially by a lysine, while hydrophobic and π-orbital containing side-chains interact with it laterally. Letters in parenthesis indicate the chain ID, with asterisk indicating symmetry equivalents.

Mentions: To elucidate the diverse effects of CRs on protein crystallization, we solved the structures of all crystals obtained in the presence of CRs. Direct interactions with CR were revealed only in hemoglobin, DMP19, RbmA, and Pin1R14A crystals (Figure 2; Supporting Information, Figure S5, Tables S2–S4). Lysozyme, SARS-CoV 3CL protease, hemoglobin, and Pin1R14A yielded crystals belonging to known space groups, whereas the addition of CR resulted in a new space group for DMP19. Addition of CR improved RbmA crystal quality and resolution, making it possible to solve the complex structure.16 On the other hand, the DMP19, Pin1R14A, and hemoglobin structures presented novel CR interactions with common characteristics (Figure 2 and 3; Supporting Information, Figure S5).


Crowning proteins: modulating the protein surface properties using crown ethers.

Lee CC, Maestre-Reyna M, Hsu KC, Wang HC, Liu CI, Jeng WY, Lin LL, Wood R, Chou CC, Yang JM, Wang AH - Angew. Chem. Int. Ed. Engl. (2014)

18-Crown-6 binding modes. The upper part of each panel illustrates the structure of the molecule, the lower part is a representation, where dashed lines represent hydrogen bonds and the red semi-circles are hydrophobic contacts. a) In the K-crown binding mode, a single lysine binds the CR axially. b) Hydrophobic and π-orbital containing side-chains interact laterally with CR. No residues interact with the central region of CR, which commonly but not always coordinates two water molecules. Letters in parenthesis indicate the chain ID. c) In the mixed KC-crown binding mode, the CR is coordinated axially by a lysine, while hydrophobic and π-orbital containing side-chains interact with it laterally. Letters in parenthesis indicate the chain ID, with asterisk indicating symmetry equivalents.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4288931&req=5

fig03: 18-Crown-6 binding modes. The upper part of each panel illustrates the structure of the molecule, the lower part is a representation, where dashed lines represent hydrogen bonds and the red semi-circles are hydrophobic contacts. a) In the K-crown binding mode, a single lysine binds the CR axially. b) Hydrophobic and π-orbital containing side-chains interact laterally with CR. No residues interact with the central region of CR, which commonly but not always coordinates two water molecules. Letters in parenthesis indicate the chain ID. c) In the mixed KC-crown binding mode, the CR is coordinated axially by a lysine, while hydrophobic and π-orbital containing side-chains interact with it laterally. Letters in parenthesis indicate the chain ID, with asterisk indicating symmetry equivalents.
Mentions: To elucidate the diverse effects of CRs on protein crystallization, we solved the structures of all crystals obtained in the presence of CRs. Direct interactions with CR were revealed only in hemoglobin, DMP19, RbmA, and Pin1R14A crystals (Figure 2; Supporting Information, Figure S5, Tables S2–S4). Lysozyme, SARS-CoV 3CL protease, hemoglobin, and Pin1R14A yielded crystals belonging to known space groups, whereas the addition of CR resulted in a new space group for DMP19. Addition of CR improved RbmA crystal quality and resolution, making it possible to solve the complex structure.16 On the other hand, the DMP19, Pin1R14A, and hemoglobin structures presented novel CR interactions with common characteristics (Figure 2 and 3; Supporting Information, Figure S5).

Bottom Line: We elucidated the crystal structures of several protein-crown ether co-crystals grown in the presence of 18-crown-6.We then employed biophysical methods and molecular dynamics simulations to compare these complexes with the corresponding apoproteins and with similar complexes with ring-shaped low-molecular-weight polyethylene glycols.Consequently, we propose that crown ethers can be used to modulate a wide variety of protein surface behaviors, such as oligomerization, domain-domain interactions, stabilization in organic solvents, and crystallization.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biological Chemistry, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529 (Taiwan); Core Facilities for Protein Structural Analysis, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529 (Taiwan).

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