Stable Variants of Protein Domains Discovery Services

Stable proteins become more needed in biological research and clinical treatment. For over a decade of experience, Creative Biolabs is dedicated to providing our clients with high-quality services in phage display library construction and screening. Our scientists are proud to introduce our high-quality service of the discovery of stable proteins under different harsh conditions, including heat, protease treatment, high or low pH, or protein denaturants.

The Characteristics of Phage Particles to Resist to Specific Environmental Pressure

Since phage particles are intrinsically very stable macromolecules, these particles can be subjected to conditions that disrupt the three-dimensional structure of proteins but without affecting the integrity and infectivity of the phage particle. For example, bacteriophage M13 particles can be heated or incubated in protein denaturants, acidic or basic solutions, certain organic solvents, and proteases, without loss of infectivity. The minor coat protein, protein III (pIII) of bacteriophage M13 has three domains: C-terminal (CT) domain and two N-terminal domains (N1 and N2). Studies have shown that various proteins, such as barnase protein, ribonuclease T1, b-lactamase, and cold shock protein B, were inserted between the N2 and CT domains of the minor coat protein without disturbing the infectivity of the recombinant phage particle. Phage display library of variants can be subjected to pressure mentioned above, then protein variants that remain active are enriched during each subsequent round of screening. These properties have been used for isolating variants with resistance to specific environmental pressure.

Constructing a phage-displayed library of protein domain variants (Pershad & Kay 2013)Fig.1 Constructing a phage-displayed library of protein domain variants (Pershad & Kay 2013).

Strategies for the Identification of Stable Variant in Creative Biolabs

With years of research and development experience in phage display technology, Creative Biolabs has accumulated extensive experience in Phage Display Library Construction and Phage Display Library Screening. For phage display variants library construction, protein variants can be subcloned between the N2 and CT domains of the pIII or subcloned in-frame with the gene III coding sequence and an N-terminal affinity tag. When subjected to selective pressure, such as heat, protease treatment, high or low pH, or protein denaturants, protein variants that remain folded and active will be isolated and enriched after several rounds of biopanning. Combined with our advanced Magic™ platform, stable protein variants against specific pressure in the enriched sublibrary can be identified efficiently and effectively.

Key Advantages of Stable Variants Discovery Service

Equipped with world-leading phage display platform and professional scientific staff in phage display technology, we also provide a series of analysis services including but not limit to:

Creative Biolabs is pleased to share our cutting-edge technology and extensive expertise in the discovery of stable protein variants to facilitate our clients’ relevant research and project development. We can offer high-quality custom services by adjusting protocols to meet every unique requirement. For more detailed information, please feel free to contact us or directly send us an inquiry.


  1. Pershad, K.; Kay, B.K. Generating thermal stable variants of protein domains through phage display. Methods. 2013, 60(1):38-45.

All listed customized services & products are for research use only, not intended for pharmaceutical, diagnostic, therapeutic or any in vivo human use.

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