Editing Peptide (section)

== Protein-peptide interactions ==
[[File:Protein-peptide interaction.png|thumb|Example of a protein (orange) and peptide (green) interaction. Obtained from Propedia: a peptide-protein interactions database.<ref>{{Cite web |title=Propedia v2.3 - Peptide-Protein Interactions Database |url=http://bioinfo.dcc.ufmg.br/propedia2/ |access-date=2023-03-28 |website=bioinfo.dcc.ufmg.br}}</ref>]]
Peptides can perform interactions with proteins and other macromolecules. They are responsible for numerous important functions in human cells, such as cell signaling, and act as immune modulators.<ref name=":0">{{Cite journal |last=Martins |first=Pedro M. |last2=Santos |first2=Lucianna H. |last3=Mariano |first3=Diego |last4=Queiroz |first4=Felippe C. |last5=Bastos |first5=Luana L. |last6=Gomes |first6=Isabela de S. |last7=Fischer |first7=Pedro H. C. |last8=Rocha |first8=Rafael E. O. |last9=Silveira |first9=Sabrina A. |last10=de Lima |first10=Leonardo H. F. |last11=de Magalhães |first11=Mariana T. Q. |last12=Oliveira |first12=Maria G. A. |last13=de Melo-Minardi |first13=Raquel C. |date=December 2021 |title=Propedia: a database for protein–peptide identification based on a hybrid clustering algorithm |journal=BMC Bioinformatics |language=en |volume=22 |issue=1 |page=1 |doi=10.1186/s12859-020-03881-z |issn=1471-2105 |pmc=7776311 |pmid=33388027 |doi-access=free}}</ref> Indeed, studies have reported that 15-40% of all protein-protein interactions in human cells are mediated by peptides.<ref>{{Cite journal |last=Neduva |first=Victor |last2=Linding |first2=Rune |last3=Su-Angrand |first3=Isabelle |last4=Stark |first4=Alexander |last5=Masi |first5=Federico de |last6=Gibson |first6=Toby J |last7=Lewis |first7=Joe |last8=Serrano |first8=Luis |last9=Russell |first9=Robert B |date=2005-11-15 |editor-last=Matthews |editor-first=Rowena |title=Systematic Discovery of New Recognition Peptides Mediating Protein Interaction Networks |journal=PLOS Biology |language=en |volume=3 |issue=12 |pages=e405 |doi=10.1371/journal.pbio.0030405 |issn=1545-7885 |pmc=1283537 |pmid=16279839 |doi-access=free}}</ref> Additionally, it is estimated that at least 10% of the pharmaceutical market is based on peptide products.<ref name=":0" />