- E. Houtzager (1)
- J.H. Ippel (1)
- H.C.M. Kester (2)
- G.H. Krooshof (2)
- A.F.A. Kuijpers (1)
- X. Li (1)
- R. Linden van der (1)
- M. Ottens (1)
- G. Roo de (2)
- R.A. Samson (2)
- P.C. Sijmons (1)
- J.J.M. Vervoort (1)
- T.C. Verwoerd (1)
- I.M.C. Vijn (1)
- J. Visser (2)
- P.J.I. Vondervoort van de (2)
- R.P. Vries de (2)
- W. Willebrands (1)
Self-packed filter plates: a good alternative for pre-packed filter plates for developing purification processes of therapeutic proteins
Li, X. ; Roo, G. de; Burgers, K. ; Ottens, M. ; Eppink, M.H.M. - \ 2012
Biotechnology Journal 7 (2012)10. - ISSN 1860-6768 - p. 1269 - 1276.
chromatographic-separations - throughput - design
The use of high throughput screening (HTS) has successfully been applied in the past years in downstream process development of therapeutic proteins. Different HTS applications were introduced to speed up the purification process development of these proteins. In the light of these findings, studies were conducted to develop a controlled way of pipetting the right amount of resin in self-packed filter plates. In total thirteen plates were tested for suitability in a HTS application, based upon the different studies the Seahorse plate was experimentally verified as the best filter plate. Suitable conditions to prepare a self-packed plate were established so that linear correlations between resin concentration (POROS 50HS) and UV adsorption (420 nm) were obtained and the accuracy of slurry dispensing in a micro-titer plate was controlled within 1% deviation under established conditions. Overall, self packed filter plates are equipped to be used in the development of purification processes in HTS mode.
Design and structural analysis of a thermostable nine-beta-stranded immunoglobulin scaffold.
Roo, G. de; Francoijs, C.J.J. ; Ippel, J.H. ; Houtzager, E. ; Vijn, I.M.C. ; Burgers, K. ; Willebrands, W. ; Verwoerd, T.C. ; Linden, R. van der; Vervoort, J.J.M. ; Sijmons, P.C. - \ 2010
Biocatalysis and Biotransformation 28 (2010)2. - ISSN 1024-2422 - p. 99 - 107.
protein design - circular-dichroism - antibody fragments - stability
A small and stable protein scaffold, consisting of nine beta-strands and able to functionally present affinity peptide loops, was designed. Computational methods were used to predict sequences with low free energy derived from a naturally occurring single-chain camel antibody. Genes for two redesigned proteins (with respectively 88% and 76% identity with the original sequence) were synthesized and the proteins were expressed, purified, and subsequently characterized using circular dichroism (CD) and NMR experiments. The redesigned proteins appear to be monomeric and demonstrate CD and NMR spectra similar to the wild type, which is consistent with a well-packed immunoglobulin structure. These encouraging results indicate that the computational protein design method can identify amino acid sequences compatible with an immunoglobulin fold.
Aspergillus vadensis, a new species of the group of black Aspergilli
Vries, R.P. de; Frisvad, J.C. ; Vondervoort, P.J.I. van de; Burgers, K. ; Kuijpers, A.F.A. ; Samson, R.A. ; Visser, J. - \ 2005
Antonie van Leeuwenhoek: : Nederlandsch tijdschrift voor hygiëne, microbiologie en serologie 87 (2005)3. - ISSN 0003-6072 - p. 195 - 203.
performance liquid-chromatography - fragment-length-polymorphisms - niger aggregate - secondary metabolites - rflp analysis - mycotoxins - classification - cultures - strains - genes
A strain from the group of black Aspergilli was analysed in detail to determine the species to which it belongs. A detailed analysis of morphology, RFLP patterns and metabolite profiles was carried out. In addition, a phylogenetic tree was constructed for the black Aspergilli using the ITS and the -tubulin sequences of the individual strains. The new species differs by its poor growth on glycerol and galacturonate and its unique extrolite profile consisting of aurasperone B, nigragillin, asperazine and kotanins. RFLP analysis using three genes as probes also resulted in a unique pattern. These data indicate that the strain was closely related but not identical to Aspergillus foetidus, Aspergillus niger and Aspergillus tubingensis. It was therefore designated as a novel species and named Aspergillus vadensis
A new black Aspergillus species, A. vadensis, is a promising host for homologous and heterologous protein production
Vries, R.P. de; Burgers, K. ; Vondervoort, P.J.I. van de; Frisvad, J.C. ; Samson, R.A. ; Visser, J. - \ 2004
Applied and Environmental Microbiology 70 (2004)7. - ISSN 0099-2240 - p. 3954 - 3959.
filamentous fungi - niger - acid
A new species of the group of black aspergilli, Aspergillus vadensis, was analyzed for its potential as a host for homologous and heterologous protein production. Unlike the other black aspergilli, this strain does not acidify the culture medium when nitrate is the nitrogen source and only produces very low levels of extracellular proteases, mainly serine metalloproteases. The stability of A. tubingensis feruloyl esterase A (FaeA) was compared upon production in wild-type A. vadensis, A. tubingensis, and an A. niger strain in which the three main protease-encoding genes were disrupted. The production of FaeA in A. vadensis resulted in larger amounts of intact protein than production in A. tubingensis and was similar to production in an A. niger protease disruptant, confirming in vivo the low proteolytic activity of A. vadensis. The protoplast formation and transformation efficiencies of A. vadensis were much higher than those of A. niger. These characteristics make A. vadensis a very promising candidate for homologous, and possibly heterologous, protein production.
|Endopolygalacturonases van Botrytris cinerea: karakteristieken in vitro
Krooshof, G.H. ; Kester, H.C.M. ; Burgers, K. ; Benen, J.A.E. - \ 2003
In: Volume of Abstracts: 11-th International Congress on Molecular Plant-Microbe Interactions, St.-Petersburg, Russia, 18-26 July 2003 - p. 132 - 132.
Endopolygalacturonases van Botrytis cinerea: karakteristieken in vitro
Krooshof, G.H. ; Kester, H.C.M. ; Burgers, K. ; Benen, J.A.E. - \ 2003
Gewasbescherming 34 (2003)1. - ISSN 0166-6495 - p. 17 (1) - 17 (1).
plantenziektekunde - botrytis - houtachtige planten als sierplanten - aardbeien - gewasbescherming - organismen ingezet bij biologische bestrijding - antagonisme - onderzoek - bloembollen - paeonia - plant pathology - botrytis - ornamental woody plants - strawberries - ornamental bulbs - paeonia - plant protection - biological control agents - antagonism - research
In dit artikel samenvattingen van lezingen van zeven presentaties van zestien onderzoekers van de KNPV-werkgroep Botrytis die op 18 september 2002 hun jaarlijkse bijeenkomst op het PPO Bomen in Boskoop hielden. De lezingen hadden de volgende onderwerpen: 1) Botrytis problems in hardy ornamentals; 2) Epidemiologie van Botrytis paeoniae in pioenroos; 3) Bestrijding van Botrytis in aardbeien met de hulp van een BOS, gericht op BoWaS; 4) Ulocladium is Botrytis een sla voor, maar nog niet praktijkrijp; 5) Endopolygalacturonases van Botrytis cinerea: karakteristieken in vitro; 6) De rol van endopolygalacturonases in het infectieproces van Botrytis cinerea; 7) Beheersing van Botrytis spp., veroorzaker van 'vuur' in bolgewassen, met behulp van anatagonistische micro-organismen