Secretory expression and characterization of a recombinant-deleted variant of human hepatocyte growth factor in Pichia pastoris

Efficient expression of a cytokine combination in Saccharomyces cerevisiae for cultured meat production

Cultured meat technology is a novel and promising alternative strategy for meat production, and it provides an efficient, safe, and sustainable way to supply animal protein. Cytokines play an important role in promoting the rapid proliferation of cells, but the high cost and potential food safety concerns of commercial cytokines have hindered their application in large-scale cultured meat production. Herein, Saccharomyces cerevisiae C800 was used as a starting strain in which four cytokines were exogenously expressed simultaneously using the Cre-loxP system, including long-chain human insulin growth factor-1, platelet-derived growth factor-BB, basic fibroblast growth factor, and epidermal growth factor. Through promoter optimization, endogenous protease knockout, genomic co-expression, expression frame gene order optimization, and fermentation optimization, a recombinant strain CPK2B2 co-expressing four cytokines was obtained with a yield of 18.35 mg/L. After cell lysis and filter sterilization, the CPK2B2 lysate was directly added to the culture medium of porcine muscle satellite cells (MuSCs). CPK2B2 lysate promoted the growth of MuSCs and increased the proportion of G2/S cells and EdU⁺ cells significantly, indicating its efficacy in promoting cell proliferation. This study provides a simple and cost-saving strategy by using S. cerevisiae to produce a recombinant cytokine combination for cultured meat production.

Carbohydrate synthesis and biosynthesis technologies for cracking of the glycan code: recent advances

The glycan code of glycoproteins can be conceptually defined at molecular level by the sequence of well characterized glycans attached to evolutionarily predetermined amino acids along the polypeptide chain. Functional consequences of protein glycosylation are numerous, and include a hierarchy of properties from general physicochemical characteristics such as solubility, stability and protection of the polypeptide from the environment up to specific glycan interactions. Definition of the glycan code for glycoproteins has been so far hampered by the lack of chemically defined glycoprotein glycoforms that proved to be extremely difficult to purify from natural sources, and the total chemical synthesis of which has been hitherto possible only for very small molecular species. This review summarizes the recent progress in chemical and chemoenzymatic synthesis of complex glycans and their protein conjugates. Progress in our understanding of the ways in which a particular glycoprotein glycoform gives rise to a unique set of functional properties is now having far reaching implications for the biotechnology of important glycodrugs such as therapeutical monoclonal antibodies, glycoprotein hormones, carbohydrate conjugates used for vaccination and other practically important protein-carbohydrate conjugates.