Mechanical Properties of Natural <i>Osmia lignaria</i> Silk and Recombinant Expression of the Silk Proteins

The use of petroleum-based plastic and the subsequent waste has led researchers to explore alternatives in the form of biopolymers. Spider silk and hagfish intermediate filaments show the potential to be advantageously utilized in textile and biomedical industries. Bee silk is a sparsely studied biopolymer that has shown potential to be added to these other impressive biopolymers. Osmia lignaria, is a solitary bee native to the western United States. Silk from these bees can be isolated while the larvae are spinning their silk. The silk from these bees has been mechanically tested for strength, stress, strain, and elasticity. Cocoon fragments were also analyzed for the amino acid composition. Comparing potential sequences to known bee silk protein sequences, the O. lignaria silk proteins were identified. DNA constructs were ordered, cloned, digested, and finally ligated into high expression vector pET-19k. After transformation into Escherichia coli BL21 (DE3) cells, expression was performed. Through a Coomassie Blue staining and western blot, no protein could be observed.