Purification and immunogenicity study of human papillomavirus 58 virus-like particles expressed in Pichia pastoris

Scanning Electron Microscopy-Based Approach to Understand the Mechanism Underlying the Adhesion of Dengue Viruses on Ceramic Hydroxyapatite Columns

“…The opposite is shown in Figures 2 and 4. The consequence of HA units in the fractions and the observation of viruses in the corresponding SEM images visually confirmed that dengue viruses could be eluted by high-salt concentrations with HAp chromatography, which is consistent with the results reported by other researchers [7], [8], [9]. HAp possesses cation-exchange capabilities and calcium metal affinities, which contribute to the elution of dengue viruses.…”

“…The mechanisms underlying virus adsorption to HAp are still obscure. However, reports that have demonstrated favorable isolations of viruses have been published previously, and good results were obtained with high-salt eluting as well as with protein isolation [7], [8], [9].…”

Expression of unique chimeric human papilloma virus type 16 (HPV‐16) L1‐L2 proteins in Pichia pastoris and Hansenula polymorpha

“…Our western blot analysis revealed the presence of lower molecular weight protein species in the H. polymorpha crude cell lysates, but not in the P. pastoris KM71 crude cell lysates (Figure ). Several other groups have seen this phenomenon after expressing HPV16 L1 in insect cells (Kirnbauer et al, ), yeast (Bazan et al, ; Deschuyteneer et al, ; Jiang et al, ) and bacteria (Aires et al, ; Chen, Casini, Harrison, & Garcea, ; Kelsall & Kulski, ; Lai & Middelberg, ; Zhang et al, ). The lower molecular weight proteins are most probably degradation products of the full‐length L1 since they were not seen in total extracts of H. polymorpha before the induction of recombinant proteins (data not shown) (Bazan et al, ; Zhang et al, ).…”

“…HPV L1 VLPs have been produced in various expression systems, such as bacteria, e.g. Escherichia coli (Chen et al, 2016), yeast such as Saccharomyces cerevisiae (Woo, An, Kim, Park, & Kim, 2008), Pichia pastoris (Bazan et al, 2009;Coimbra et al, 2011;Jiang, Tong, Cai, Xu, & Lou, 2011;Kotzé, Smith, den Haan, van Zyl, & Görgens, 2011;Rao et al, 2011;Smith, Burke, Bredell, Van Zyl, & Görgens, 2012;Zhao et al, 2015) and Hansenula polymorpha (Li, He, Guo, Zhang, & Zhang, 2009), baculovirus-infected insect cells (Le Cann, Coursaget, Iochmann, & Touze, 1994), transgenic plants (Biemelt, Sonnewald, Galmbacher, Willmitzer, & Müller, 2003) and mammalian cells (McLean et al, 1990). VLPs consisting of both L1 and L2 have been produced in human epithelial cells (Cianciarullo et al, 2010) and similarly bovine papillomavirus type 4 (BPV-4) VLPs in insect cells (Kirnbauer et al, 1996).…”

Selection of downstream steps by analysis of protein surface property: A case study for recombinant human lactoferrin purification from milk of transgenic cow

“…For example, cationic exchange chromatography is proposed as the top priority in purification of basic or alkaline proteins which demonstrate high isoelectric points [4,5]. Size exclusion chromatography is often employed for virus-like particle purification because of its much greater size than other protein impurities [6,7]. However, experience prediction is rather limited when the physiological difference between the product and impurities is very small [8], especially when the two resembles each other such as purification of a human milk protein from a milk of transgenic cow.…”