Sandbox Reserved 918: Difference between revisions
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# Substrate binds to enzyme and carbonyl carbon is positioned by [http://en.wikipedia.org/wiki/Active_site active site]. | # Substrate binds to enzyme and carbonyl carbon is positioned by [http://en.wikipedia.org/wiki/Active_site active site]. | ||
# Histidine, via hydrogen bond with asparatate, becomes more [http://en.wikipedia.org/wiki/Electronegativity electronegative] and therefore readily accepts the hydrogen from the hydroxyl group on serine, making it [http://en.wikipedia.org/wiki/Nucleophile nucleophilic]. [[Image:Serine_protease_mechanism_by_snellios.png|right|thumb|150px|<font size=".8"><div style="text-align: center;"> General [http://en.wikipedia.org/wiki/File:Serine_protease_mechanism_by_snellios.png arrow pushing mechanism] for serine proteases. </div></font>]] | # Histidine, via hydrogen bond with asparatate, becomes more [http://en.wikipedia.org/wiki/Electronegativity electronegative] and therefore readily accepts the hydrogen from the hydroxyl group on serine, making it more [http://en.wikipedia.org/wiki/Nucleophile nucleophilic]. [[Image:Serine_protease_mechanism_by_snellios.png|right|thumb|150px|<font size=".8"><div style="text-align: center;"> General [http://en.wikipedia.org/wiki/File:Serine_protease_mechanism_by_snellios.png arrow pushing mechanism] for serine proteases. </div></font>]] | ||
# The nucleophilic serine attacks the [http://en.wikipedia.org/wiki/Carbonyl carbonyl] carbon, generating a [http://goldbook.iupac.org/T06289.html tetrahedral intermediate] (as seen in the [http://en.wikipedia.org/wiki/Arrow_pushing arrow pushing mechanism]). | # The nucleophilic serine attacks the [http://en.wikipedia.org/wiki/Carbonyl carbonyl] carbon, generating a [http://goldbook.iupac.org/T06289.html tetrahedral intermediate] (as seen in the [http://en.wikipedia.org/wiki/Arrow_pushing arrow pushing mechanism]). | ||
# The peptide bond is cleaved and the electrons from it move to attack the hydrogen on the histidine. This half of the substrate now dissociates, leaving the other half still covalently bound to serine. | # The peptide bond is cleaved and the electrons from it move to attack the hydrogen on the histidine. This half of the substrate now dissociates, leaving the other half still covalently bound to serine. | ||