The New Gold Standard in Protein Engineering Libraries

Lucy Xu, Libraries Product Manager at Twist Bioscience, recently outlined how Twist is building new variant libraries in a webinar titled: “Explore Sequence Space With Twist Bioscience Spread Out Low Diversity Libraries”. This webinar follows the launch of  Twist Bioscience’s new product,  Spread Out Low Diversity (SOLD) libraries. Lucy discussed how this new addition to the Twist library product family was developed for protein engineering with a focus on enzymes, offering a tool to rapidly and precisely design, investigate and optimize enzyme activity, protein stability, or solubility.

Rewriting DNA with the Power of Silicon

Twist Bioscience has developed proprietary technology to synthesize DNA on a silicon platform. The platform miniaturizes the synthesis process, allowing for the printing of up to a million oligos in the same form factor as a 96-well plate.

These oligos form the foundation for many Twist products. “We’ve leveraged our technology to build DNA variant libraries in a quick and inexpensive manner so you can have the tools you need in your hands in as little as two weeks,” commented Lucy. With access to a huge volume of high-quality oligos, each variant is built up base-by-base, so diversity can be precisely incorporated into the region of interest. Applications of this technology include protein engineering, antibody engineering, and enzyme evolution, among others.

SOLD is an Expansion of the Multiple Site Combinatorial Variant Library

Until now, Twist Bioscience has offered two variant library products: Site Saturation Variant Libraries (SSVLs) and Combinatorial Variant Libraries (CVLs). In an SSVL, each sequence represents a single amino acid variation at a specific position. Each amino acid in the protein of interest can be mutated to every other amino acid. Precise ratios of specific amino acids can also be represented if desired. In a CVL, the full combinatorial set of amino acid variants at multiple positions can be explored. Large amounts of sequence space can therefore be explored across a short protein stretch.

Lucy explained how Twist Bioscience’s new SOLD libraries bridge a gap between SSVLs and CVLs, explicitly designed for customers investigating multiple variant positions scattered throughout their gene of interest.

With SOLD libraries, researchers can:

• Build multiple libraries of up to 108 diversity each.
• Build libraries to investigate and optimize protein activity both rapidly and effectively by precisely designing multiple mutations across the wild type sequence, which can be scattered throughout the protein or localized to specific domains.
• Incorporate length variation into libraries.

SOLD library customers can also get support removing liabilities, non-specificity motifs, and any other unwanted properties in their library, thus enriching variants that are more likely to succeed.

Protein Engineering with SOLD Libraries

SOLD libraries offer a huge improvement over random mutagenesis, directed mutagenesis, and “DNA shuffling” based approaches to enzyme engineering, as only the precisely designed mutations are incorporated into the protein. SOLD libraries also allow for the uniform distribution of each amino acid per position and the removal of unwanted biases.

Check out the webinar recording to see how Twist built a SOLD library with 26 variant positions scattered throughout the protein, each position containing 2-3 mutations, including the wild type amino acid. Specifically, you will see how the SOLD library synthesis process preserves diversity without being restricted by codon bias. You will also see how the amino acid distribution matches the original design without the need for additional screening with no unintended mutations and no dropouts!

For more information on SOLD libraries, be sure to check out the product page.

To enquire about ordering a SOLD library for your next project, fill out our Contact Us form.