Binding of amino acid side-chains to S 1 cavities of serine proteinases 1 1Edited by R. Huber

Lu, Wuyuan; Apostoł, Izydor; Qasim, Mohammad; Warne, Nicholas W.; Wynn, Richard; Zhang, Wenlei; Anderson, Stephen; Chiang, Yiwen; Ogin, Eleanor; Rothberg, Irvin; Ryan, Kevin; Laskowski, M.

doi:10.1006/jmbi.1996.0781

Cited by 168 publications

(226 citation statements)

References 84 publications

Supporting

Mentioning

212

Contrasting

Unclassified

Order By: Relevance

“…All peptides were purified to homogeneity by RP-HPLC and their molecular weights verified by electrospray ionization MS (ESI-MS). ␣-aminobutyric acid (Abu) is often considered to be isosteric to Cys (29,30) and therefore was our preferred amino acid used to remove disulfide bridges in hBD3. When assessed by circular dichroism spectroscopy, [Abu]-hBD3, i.e., disulfide-devoid hBD3 in which Abu replaces all six Cys residues, was found largely unstructured in aqueous solution.…”

Section: Methodsmentioning

confidence: 99%

Engineering disulfide bridges to dissect antimicrobial and chemotactic activities of human β-defensin 3

Hoover²,

Yang³

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

413

431

View full text Add to dashboard Cite

Human defensins form a family of small, cationic, and Cys-rich antimicrobial proteins that play important roles in innate immunity against invading microbes. They also function as effective immune modulators in adaptive immunity by selectively chemoattracting T lymphocytes and immature dendritic cells. On the basis of sequence homology and the connectivity of six conserved Cys residues, human defensins are classified into ␣ and ␤ families. Structures of several ␤-defensins have recently been characterized, confirming the disulfide connectivity conserved within the family, i.e., Cys 1 -Cys 5 , Cys 2 -Cys 4 , and Cys 3 -Cys 6 . We found that human ␤-defensin 3 (hBD3), a recently described member of the growing ␤ family, did not fold preferentially into a native conformation in vitro under various oxidative conditions. Using the orthogonal protection of Cys 1 -Cys 5 and of Cys 1 -Cys 6 , we chemically synthesized six topological analogs of hBD3 with predefined disulfide connectivities, including the (presumably) native ␤ pairing. Unexpectedly, all differently folded hBD3 species exhibited similar antimicrobial activity against Escherichia coli, whereas a wide range of chemotactic activities was observed with these analogs for monocytes and cells transfected by the chemokine receptor CCR6. Furthermore, whereas substitution of all Cys residues by ␣-aminobutyric acid completely abolished the chemotactic activity of hBD3, the bactericidal activity remained unaffected in the absence of any disulfide bridge. Our findings demonstrate that disulfide bonding in hBD3, although required for binding and activation of receptors for chemotaxis, is fully dispensable for its antimicrobial function, thus shedding light on the mechanisms of action for human ␤-defensins and the design of novel peptide antibiotics.

show abstract

Section: Methodsmentioning

confidence: 99%

Engineering disulfide bridges to dissect antimicrobial and chemotactic activities of human β-defensin 3

Hoover²,

Yang³

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

413

431

View full text Add to dashboard Cite

show abstract

“…Functional Rescue of W26A-HNP1-To gain additional insights into the nature of the deleterious W26A mutation, we introduced at position 26 a homologous series of unnatural amino acids with straight aliphatic side chains: Abu, Nva, Nle, and Ahp (61). Shown in Fig.…”

Section: Trp-26 Is a Critical Residue Inmentioning

confidence: 99%

Trp-26 Imparts Functional Versatility to Human α-Defensin HNP1

Wei

Pazgier

Leeuw

et al. 2010

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

We performed a comprehensive alanine scan of human ␣-defensin HNP1 and tested the ability of the resulting analogs to kill Staphylococcus aureus, inhibit anthrax lethal factor, and bind human immunodeficiency virus-1 gp120. By far, the most deleterious mutation for all of these functions was W26A. The activities lost by W26A-HNP1 were restored progressively by replacing W26 with non-coded, straight-chain aliphatic amino acids of increasing chain length. The hydrophobicity of residue 26 also correlated with the ability of the analogs to bind immobilized wild type HNP1 and to undergo further self-association. Thus, the hydrophobicity of residue 26 is not only a key determinant of the direct interactions of HNP1 with target molecules, but it also governs the ability of this peptide to form dimers and more complex quaternary structures at micromolar concentrations. Although all defensin peptides are cationic, their amphipathicity is at least as important as their positive charge in enabling them to participate in innate host defense.

show abstract

“…On the other hand, main chain-main chain contacts and therefore the backbone geometry are much more important to proteinase-inhibitor interactions than side chain interactions and therefore the actual P1 residue (49). For example, mutational studies with proteinase-inhibitor complexes revealed that despite replacement of the P1 residue with other amino acids the same residue position served as the P1 site independent of the particular amino acid (50)(51)(52).…”

Section: The Secondary and Tertiary Structure Of Dom1pi Is Different mentioning

confidence: 99%

The Solution Structure of a Chimeric LEKTI Domain Reveals a Chameleon Sequence

et al. 2004

View full text Add to dashboard Cite

The conversion of an R-helical to a -strand conformation and the presence of chameleon sequences are fascinating from the perspective that such structural features are implicated in the induction of amyloid-related fatal diseases. In this study, we have determined the solution structure of a chimeric domain (Dom1PI) from the multidomain Kazal-type serine proteinase inhibitor LEKTI using multidimensional NMR spectroscopy. This chimeric protein was constructed to investigate the reasons for differences in the folds of the homologous LEKTI domains 1 and 6 [Lauber, T., et al. (2003) J. Mol. Biol. 328, 205-219]. In Dom1PI, two adjacent phenylalanine residues (F28 and F29) of domain 1 were substituted with proline and isoleucine, respectively, as found in the corresponding P4′ and P5′ positions of domain 6. The three-dimensional structure of Dom1PI is significantly different from the structure of domain 1 and closely resembles the structure of domain 6, despite the sequence being identical to that of domain 1 except for the two substituted phenylalanine residues and being only 31% identical to the sequence of domain 6. The mutation converted a short 3 10 -helix into an extended loop conformation and parts of the long COOH-terminal R-helix of domain 1 into a -hairpin structure. The latter conformational change occurs in a sequence stretch distinct from the region containing the substituted residues. Therefore, this switch from an R-helical structure to a -hairpin structure indicates a chameleon sequence of seven residues. We conclude that the secondary structure of Dom1PI is determined not only by the local protein sequence but also by nonlocal interactions.

show abstract

Binding of amino acid side-chains to S 1 cavities of serine proteinases 1 1Edited by R. Huber

Cited by 168 publications

References 84 publications

Engineering disulfide bridges to dissect antimicrobial and chemotactic activities of human β-defensin 3

Engineering disulfide bridges to dissect antimicrobial and chemotactic activities of human β-defensin 3

Trp-26 Imparts Functional Versatility to Human α-Defensin HNP1

The Solution Structure of a Chimeric LEKTI Domain Reveals a Chameleon Sequence

Contact Info

Product

Resources

About