Editing Side-chain theory (section)

==History==

In 1891, Paul Ehrlich joined the newly established [[Robert Koch Institute]] in Berlin upon the invitation of [[Robert Koch]] himself.<ref>{{cite journal|last1=Kasten|first1=FH|title=Paul Ehrlich: pathfinder in cell biology. 1. Chronicle of his life and accomplishments in immunology, cancer research, and chemotherapy.|journal=Biotechnic & Histochemistry|year=1996|volume=71|issue=1|pages=2–37|pmid=9138526|doi=10.3109/10520299609117128}}</ref> By 1896 a new branch, the Institute for Serum Research and Testing (Institut für Serumforschung und Serumprüfung), was established in Frankfurt with Ehrlich as its founding director.<ref>{{cite journal|last1=Valent|first1=Peter|last2=Groner|first2=Bernd|last3=Schumacher|first3=Udo|last4=Superti-Furga|first4=Giulio|last5=Busslinger|first5=Meinrad|last6=Kralovics|first6=Robert|last7=Zielinski|first7=Christoph|last8=Penninger|first8=Josef M.|last9=Kerjaschki|first9=Dontscho|last10=Stingl|first10=Georg|last11=Smolen|first11=Josef S.|last12=Valenta|first12=Rudolf|last13=Lassmann|first13=Hans|last14=Kovar|first14=Heinrich|last15=Jäger|first15=Ulrich|last16=Kornek|first16=Gabriela|last17=Müller|first17=Markus|last18=Sörgel|first18=Fritz|title=Paul Ehrlich (1854-1915) and His Contributions to the Foundation and Birth of Translational Medicine|journal=Journal of Innate Immunity|year=2016|volume=8|issue=2|pages=111–20|doi=10.1159/000443526|pmid=26845587|pmc=6738855 |doi-access=free}}</ref> He worked on antitoxins for [[diphtheria]] and their binding to antibodies in the blood. He hypothesised that antibodies bind to antigens through special chemical structures that he called "side chains" (which he later named "receptors"). Borrowing a concept used by [[Hermann Emil Fischer|Emil Fischer]] in 1894 to explain the interaction between an enzyme and its substrate, Ehrlich proposed that binding of the receptor to an infectious agent was like the fit between a lock and key. He published the first part of his side-chain theory in 1897, and its full form in 1900 in a lecture he delivered to the [[Royal Society]] in London.<ref name="ziel">{{cite journal|last1=Zielinska|first1=Edyta|title=Side-Chain Theory, circa 1900|journal=The Scientist|year=2013|volume=online|url=http://www.the-scientist.com/?articles.view/articleNo/36175/title/Side-Chain-Theory--circa-1900/}}</ref>