10.1021/acs.langmuir.8b02950.s002 A. Pasha Tabatabai A. Pasha Tabatabai Benjamin P. Partlow Benjamin P. Partlow Nicole R. Raia Nicole R. Raia David L. Kaplan David L. Kaplan Daniel L. Blair Daniel L. Blair Silk Molecular Weight Influences the Kinetics of Enzymatically Cross-linked Silk Hydrogel Formation American Chemical Society 2018 silk Molecular Weight Influences reconstituted silk solutions bulk rheological properties weight changes covalent dityrosine cross-linking Enzymatically Cross-linked Silk Hydrogel Formation protein hydrogel time-resolved bond formation mechanism polymerization gelation process growth postpercolation covalent dityrosine bond formation polymerize model mode Kinetic 2018-11-13 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Silk_Molecular_Weight_Influences_the_Kinetics_of_Enzymatically_Cross-linked_Silk_Hydrogel_Formation/7388681 We transform reconstituted silk solutions into robust hydrogels through covalent dityrosine cross-linking resulting from an enzymatic reaction. The bulk rheological properties and the covalent dityrosine bond formation of these gels are measured during polymerization. We compare the time-resolved bond formation to the mechanical properties, where we find that the gelation process is consistent with a model of percolation. The molecular weight of the protein determines whether a secondary mode of growth postpercolation exists, indicating that molecular weight changes affect the mechanisms by which these gels polymerize.