Folded proteins occur frequently in libraries of random amino acid sequences.

@article{Davidson1994FoldedPO,
  title={Folded proteins occur frequently in libraries of random amino acid sequences.},
  author={Alan R. Davidson and Robert T. Sauer},
  journal={Proceedings of the National Academy of Sciences of the United States of America},
  year={1994},
  volume={91 6},
  pages={2146-50}
}
A library of synthetic genes encoding 80- to 100-residue proteins composed mainly of random combinations of glutamine (Q), leucine (L), and arginine (R) has been expressed in Escherichia coli. These genes also encode an epitope tag and six carboxyl-terminal histidines. Screening of this library by immunoblotting showed that 5% of these QLR proteins are expressed at readily detectable levels. Three well-expressed QLR proteins were purified and characterized. Each of these proteins has… CONTINUE READING