Versatile Cyclic Templates for Assembly of Axially Oriented Ligands
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- 作者：Neeraj Chopra§ ; ; Wenxun Gan‡ ; ; Hans Schreiber§ ; ; Josh W. Kurutz† ; ; Stephen C. Meredith*§ ; † ;
- 刊名：Bioconjugate Chemistry
- 出版年：2009
- 出版时间：February 18, 2009
- 年：2009
- 卷：20
- 期：2
- 页码：231-240
- 全文大小：422K
- 年卷期：v.20,no.2(February 18, 2009)
- ISSN：1520-4812
文摘
In this paper, we describe two novel types of planar cyclic peptide templates for the facile addition of ligands that extend axially from the plane of the template ring. The first uses β-amino acids of alternating class="smallcaps">d- and class="smallcaps">l-chirality, since the insertion of the additional methylene group in the peptide backbone was predicted and subsequently shown by NMR and molecular modeling, to reorient ligands attached to amino acid side chain axially with respect to the template ring. A second contains alternating class="smallcaps">d- and class="smallcaps">l-amino acids with an achiral Gly residue interposed between each chiral amino acid. The inserted Gly residues also tend to reorient side chains axially rather than radially, as was demonstrated by NMR and molecular modeling. The axial orientation of attached ligands is intended to foster or allow interactions among attached ligands in situations in which this is desired. Two such situations that we consider are (1) development of immunological reagents with avidity effects and (2) modeling of oligomers in fibril-forming peptides. Toward the first of these goals, we demonstrated that these templates are suitable for attaching macromolecules, by incorporating two types of protein, neutravidin and trypsinogen. Toward the second goal, we demonstrate the attachment of two different fibril-forming peptides to the template. The templates described herein thus have many of the desirable traits of such molecules, i.e., (1) multivalency for the attachment of multiple ligands, (2) suitable chemical functions for facile attachment of ligands, (3) versatility as to the number and spacing of ligand attachment sites, (4) sufficient rigidity so that the attached ligands can be similarly oriented with respect to the template, and (5) sufficient flexibility to allow even large ligands, such as proteins, to attach and interact.