Foam fractionation of a recombinant biosurfactant apolipoprotein

• Published in: Journal of biotechnology 2022-01, Vol.343, p.25-31
• Main Authors: Lethcoe, Kyle, Fox, Colin A., Ryan, Robert O.
• Format: Article
• Language: English
• Subjects: Animals; Apolipoprotein; Apolipoproteins - biosynthesis; Bioreactor; Chemical Fractionation; Escherichia coli - genetics; Foam fractionation; Insect Proteins - biosynthesis; Locusta migratoria; Nanodisk; Phospholipids; Recombinant Proteins - biosynthesis; Reconstituted high density lipoprotein
• ISSN: 0168-1656; 1873-4863
• DOI: 10.1016/j.jbiotec.2021.11.004

Locusta migratoria apolipophorin III (apoLp-III) possesses the ability to exist as a water soluble amphipathic α-helix bundle and a lipid surface seeking apolipoprotein. The intrinsic ability of apoLp-III to transform phospholipid vesicles into reconstituted discoidal high-density lipoproteins (rHDL) has led to myriad applications. To improve the yield of recombinant apoLp-III, studies were performed in a bioreactor. Induction of apoLp-III expression generated a protein product that is secreted from E. coli into the culture medium. Interaction of apoLp-III with gas and liquid components in media produced large quantities of thick foam. A continuous foam fractionation process yielded a foamate containing apoLp-III as the sole major protein component. The yield of recombinant apoLp-III was ~0.2 g / liter bacterial culture. Mass spectrometry analysis verified the identity of the target protein and indicated no modifications or changes to apoLp-III occurred as a result of foam fractionation. The functional ability of apoLp-III to induce rHDL formation was evaluated by incubating foam fractionated apoLp-III with phosphatidylcholine vesicles. FPLC size exclusion chromatography revealed a single major population of particles in the size range of rHDL. The results described offer a novel approach to bioreactor-based apoLp-III production that takes advantage of its intrinsic biosurfactant properties. •Apolipophorin III (apoLp-III) is a apolipoprotein with biosurfactant properties.•Recombinant apoLp-III with a pelB leader sequence is secreted from E. coli.•In a bioreactor, apoLp-III combines with gas and liquid in media to produce foam.•Foam fractionation can be used to streamline downstream processing of apoLp-III.•ApoLp-III has numerous biotechnology applications as a nanodisks scaffold.