Peptide-Binding Domains: Are Limp Handshakes Safest?

Sci. Signal., 25 September 2012
Vol. 5, Issue 243, p. pe40
DOI: 10.1126/scisignal.2003372

Peptide-Binding Domains: Are Limp Handshakes Safest?

  1. Niall J. Haslam and
  2. Denis C. Shields*
  1. UCD Complex and Adaptive Systems Laboratory, UCD School of Medicine and Medical Sciences, and UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland.
  1. *Corresponding author. E-mail: denis.shields{at}


Interactions between short peptides within proteins and peptide-binding domains can trigger many important cell signaling processes, and their interactions are typically of modest affinity. A study showed that this modest affinity appears to be favored by evolution. They used phage display selection to discover “superbinder” Src Homology 2 (SH2) domains, which bound peptides with much stronger affinity than naturally occurring SH2 domains. These superbinder domains had strong biological effects, such as blocking cell signaling. Although the superbinders had higher affinity, this did not appear to reduce their specificity. In contrast, SH2-binding peptides from bacterial pathogens have evolved to exhibit promiscuity of binding to multiple SH2 domains, carried within effector proteins that subvert signaling upon entry into the mammalian cell. Because there are many potential peptide binders of the SH2 domain found in numerous human proteins, modest affinity not only may optimize transient signaling mediated by reversible interactions but also may minimize off-target deleterious binding effects. The stage is set for a more thorough evaluation of the specificity and off-target impact of both naturally occurring and artificial domains and peptides. This may help define both targets and reagents for therapeutic intervention in key signaling processes mediated by short peptides.


N. J. Haslam and D. C. Shields, Peptide-Binding Domains: Are Limp Handshakes Safest?. Sci. Signal. 5, pe40 (2012).

Controlling for Gene Expression Changes in Transcription Factor Protein Networks
C. A. S. Banks, Z. T. Lee, G. Boanca, M. Lakshminarasimhan, B. D. Groppe, Z. Wen, G. L. Hattem, C. W. Seidel, L. Florens, M. P. Washburn et al.
MCP 13, 1510-1522 (1 June 2014)

The eukaryotic linear motif resource ELM: 10 years and counting
H. Dinkel, K. Van Roey, S. Michael, N. E. Davey, R. J. Weatheritt, D. Born, T. Speck, D. Kruger, G. Grebnev, M. Kuban et al.
Nucleic Acids Res 42, D259-D266 (1 January 2014)

Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882