Sequence, structure, and function of peptide self-assembled monolayers

Citation

Nowinski, Ann K.; Sun, Fang; White, Andrew D.; Keefe, Andrew J.; & Jiang, Shaoyi (2012). Sequence, structure, and function of peptide self-assembled monolayers. Journal of the American Chemical Society, 134(13), 6000-6005.

Abstract

Cysteine is commonly used to attach peptides onto gold surfaces. Here we show that the inclusion of an additional linker with a length of four residues (-PPPPC) and a rigid, hydrophobic nature is a better choice for forming peptide self-assembled monolayers (SAMs) with a well-ordered structure and high surface density. We compared the structure and function of the nonfouling peptide EKEKEKE-PPPPC-Am with EKEKEKE-C-Am. Circular dichroism, attenuated total internal reflection Fourier transform IR spectroscopy, and molecular dynamics results showed that EKEKEKE-PPPPC-Am forms a secondary structure while EKEKEKE-C-Am has a random structure. Surface plasmon resonance sensor results showed that protein adsorption on EKEKEKE-PPPPC-Am/gold is very low with small variation while protein adsorption on EKEKEKE-C-Am/gold is high with large variation. X-ray photoelectron spectroscopy results showed that both peptides have strong gold-thiol binding with the gold surface, indicating that their difference in protein adsorption is due to their assembled structures. Further experimental and simulation studies were performed to show that -PPPPC is a better linker than -PC, -PPC, and -PPPC. Finally, we extended EKEKEKE-PPPPC-Am with the cell-binding sequence RGD and demonstrated control over specific versus nonspecific cell adhesion without using poly(ethylene glycol). Adding a functional peptide to the nonfouling EK sequence avoids complex chemistries that are used for its connection to synthetic materials.

Keyword(s)

Amino Acid Sequence
Biofouling
gold
Models, Molecular
Oligopeptides
Protein Structure, Secondary
Solutions
Surface Properties

Reference Type

Journal Article

Secondary Title

Journal of the American Chemical Society

Author(s)

Nowinski, Ann K.
Sun, Fang
White, Andrew D.
Keefe, Andrew J.
Jiang, Shaoyi

Year Published

2012

Date Published

1333497600

Volume Number

134

Issue Number

Pages

6000-6005

ISSN/ISBN

1520-5126

DOI

10.1021/ja3006868