Secretion purification

Ferrari, E., Lodi, T., Sorbi, R. T., Tirindelli, R., Cavaggioni, A. Spisni, A., 1997. Expression of a lipocalin in Pichiapastoris Secretion, purification and binding activity of a recombinant mouse major urinary protein. FEBS Letters. 401, 73-77... 

Slos, P., Speck, D., Accart, N., Kolbe, H.V., Schubnel, D., Bouchon, B., Bischoff, R., and Kieny, M.P., 1994, Recombinant Cholera Toxin B Subunit in E. Coli High-level Secretion, Purification, and Characterization, In Protein Expression Purif, 5, 518-26... 

Yeast. The advantages of expression in yeast include potentially high level production of proteins, the abiUty to have expressed proteins secreted into the media for ease of purification, and relatively low cost, easy scale-up. A disadvantage is that plasmid instabiUty may be a problem which can lead to low product yield. Whereas post-translational modification occurs in yeast, proteins are quite often hyperglycosylated. This is generally a problem with expression in Saccharomyces cerevisiae but not for the more recently used yeast host Pichiapastoris (25) (see Yeasts). 

An improved method of producing recombinant aequorin was devised based on the fact that the expression of the peak amount of apoaequorin in bacterial cells occurs several hours before the secretion into culture medium (Shimomura and Inouye, 1999). The cells containing apoaequorin in the periplasmic space, before secretion, are extracted under a very mild condition and, at the same time, converted into aequorin. The purification of the extract by two steps of column chromatography yields a high-purity preparation of recombinant aequorin. 

Fibrinolytic effecting protease enzyme with glycoprotein structure relative mol mass ca. 30000. Isolation from the poison secretion (venom) of Agkistrodon rhodostoma (malayan pit viper) with chromatographic purification. 

Jiang X.C., Inouchi J., Wang D. and Halpem M. (1990). Purification and characterisation of a chemoattractant from earthworm electric-shock-induced secretion and vomeronasal system in Garter snakes. J Biol Chem 265, 8736-8744. 

Valente AJ, Graves DT, Vialle-Valentin CE, Delgado R, Schwartz CJ. Purification of a monocyte chemotactic factor secreted by nonhuman primate vascular cells in culture. Biochemistry 1988 27(11) 4162 1168. 

Grigg, M.E., Tang, L., Hussein, A.S. and Selkirk, M.E. (1997) Purification and properties of monomeric (Gl) forms of acetylcholinesterase secreted by Nippostrongylus brasiliensis. Molecular and Biochemical Parasitology 90, 513-524. 

LSBC has a long history of process development, scale-up and manufacturing experience, since its foundation back in 1987. The company has developed proprietary, industrial-scale extraction processes for the purification of proteins, peptides, and other biochemicals from plant biomass. It has also developed commercial methods for the extraction and purification of secreted plant proteins. 

Proteins produced in plant cells can remain within the cell or are secreted into the apoplast via the bulk transport (secretory) pathway. In whole plants, because levels of protein accumulated intracellularly, e. g. using the KDEL sequence to ensure retention in the endoplasmic reticulum, are often higher than when the product is secreted [58], foreign proteins are generally not directed for secretion. However, as protein purification from plant biomass is potentially much more difficult and expensive than protein recovery from culture medium, protein secretion is considered an advantage in tissue culture systems. For economic harvesting from the medium, the protein should be stable once secreted and should accumulate to high levels in the extracellular environment. 

Transgenic plants, secretion from roots or leaves Containment, purification Scale, cost of production facilities... 

Cell or tissue culture Timescale, containment, secretion into medium (purification), regulatory compliance Cost, scalability... 

Zhao, Y., Jin, Y., Wei, S.-S., Lee, W.-H. and Zhang, Y. (2005) Purification and characterization of an irreversible serine protease inhibitor from skin secretions of Bufo andrewsi. Toxicon. 46, 635-640. 

Saccharomyces cerevisiae Good secretion machinery Post-translational modifications Easy scale-up Selection procedure required Tendency to overglycosylation Thick cell wall complicates purification... 

Polyesters are also produced naturally in some animals. In particular, shellac is a natural product that was for many years of major commercial importance as a moulding resin (e.g. for phonograph records) and a varnish. It is a constituent of lac, which is secreted by the lac insect of S. E. Asia and exuded by it onto trees. Shellac, which is obtained by purification from lac, is a complex polyester which can be hydrolysed to polyhydroxylic acids such as 9,10,16-trihydroxyhexadecanoic acid [97],... 

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