Science Center Spotlight
Use of Pichia Classic to produce small antibody-like protein scaffolds
Kurt R. Gehlsen, Ph.D.
Proteins that require complex folding and contain disulfide bonds can be, depending on the protein, difficult to express in E. coli. However, Pichia is a proven host for expressing and secreting properly-folded, complex proteins that retain their structure and function. As development progresses for the alternative antibody-like protein scaffolds, it has been reported that Pichia is fast becoming the production strain of choice. Single antibody domains, CH2 domains (ABDURINS), camelid VH domains (Nanobodies®), scFV and Fabs have all demonstrated high levels of expression in Pichia. Ablynx, B.V. has reported on using Pichia for large scale manufacturing for several of their Nanobody® products. In pilot expression studies for the ABDURIN platform, more than 1gm/L of CH2 domain variants have been produced using Pichia. Based on these and other results, it is highly recommended that Pichia be tested for expression of alternative binding scaffolds.
Eliot Smith et al., 2014, have recently published on the expression of recombinant human mast cell chymase (rhChymase) using the SuperMan5 Pichia GlycoSwitch® strain. Purified rhChymase was reported to be homogeneously glycosylated and enzymatically similar to isolated human chymase. This report is another example of the utility of the Pichia GlycoSwitch® System to generate recombinant proteins with human glycosylation patterns.
Pichia Expression Platform
RCT’s Pichia Expression Platform includes the Pichia Classic System and the Pichia GlycoSwitch® System. Pichia Classic is used for producing non-glycosylated proteins, or for proteins in which yeast glycosylation is acceptable. Pichia GlycoSwitch® is used for producing glycoproteins with human-like glycosylation.
Protein Expression in Pichia
Pichia pastoris is the yeast species most commonly used to produce recombinant proteins, and more than 1500 academic and industrial laboratories around the world employ it to make proteins for medical and research applications. Pichia has become an important host for recombinant protein expression because it offers high cell density, high yields, controllable processes, stability and durability. Pichia also efficiently secretes heterologous proteins in defined media to save time and cost associated with purification. RCT’s Pichia Classic System can be initially tested through the purchase of various kits and services from RCT’s partner, Life Technologies. RCT’s Pichia GlycoSwitch® System is available through the purchase of various kits and services from RCT’s partner BioGrammatics.
More than 5,000 proteins have been made using RCT’s Pichia Expression Platform and over 70 Pichia produced protein products have reached the market. With this success, Pichia has become an established host for manufacturing biopharmaceuticals with 20 products either in development or on the market from RCT’s Pichia Classic System. Examples of biopharmaceutical proteins made in Pichia include human insulin, a vaccine against hepatitis ß, human interferon-alpha, human serum albumin, microplasmin, ecallantide, monoclonal antibodies and antibody fragments.
For more information on products on the market or in development from Pichia see Commercialized Products.
To learn more about the utility of the Pichia Expression platform and its history, read the article by James M. Cregg, Ph.D. A molecular and cellular biologist with particular expertise and interest in yeasts, Cregg has played a major pioneering role in developing the Pichia Expression Platform.