Showing papers on "Pichia pastoris published in 1988"
TL;DR: TNF contained in P. pastoris cell lysates was biologically active as determined by its cytotoxic effect on murine L‐929 fibroblast cells and the bioactivity was retained for at least 6 months in the lysate stored frozen at −20 °C in the presence of protease inhibitor PMSF.
Abstract: Expression of human tumor necrosis factor-alpha (TNF) and four different TNF analogs has been studied in Pichia pastoris by utilizing the alcohol oxidase gene promoter. TNF expression level in certain transformants accounted for as much as 36% of the soluble protein. TNF expression was stably maintained during high cell density fermentation (100 g dry cell weight/liter) resulting in a TNF production level of 6-10 g/liter. TNF contained in P. pastoris cell lysates was biologically active as determined by its cytotoxic effect on murine L-929 fibroblast cells and the bioactivity was retained for at least 6 months in the lysates stored frozen at -20 degrees C in the presence of protease inhibitor PMSF. TNF expressed in P. pastoris was recognized by monoclonal antibodies prepared against recombinant Escherichia coli derived TNF. TNF purified from P. pastoris has the expected N-terminal amino acid sequence and specific activity of 10(7) units/mg protein. TNF analogs were also expressed at levels comparable to that of native TNF. Three of the four analogs were insoluble when produced in P. pastoris.
110 citations
01 Jan 1988
87 citations
TL;DR: Feeding regimes were evaluated in an effort to increase the biomass concentration and productivity that could be achieved from fermentations using Pichia pastoris, and biomass concentrations were increased 10‐fold over those achieved in batch fermentations.
Abstract: Pichia pastoris is a methylotrophic yeast that makes use bf the enzyme alcohol oxidase to catalyze the first step of the dissimilatory pathway that enables it to grow on methanol. Because of its stability and low substrate specificity, alcohol oxidase is of considerable interest for a range of biotechnological processes. Various feeding regimes were evaluated in an effort to increase the biomass concentration and productivity that could be achieved from fermentations using this organism. Through continuous or semicontinuous feeding, biomass concentrations were increased 10-fold over those achieved in batch fermentations. In subsequent trials, nongrowing whole cells were applied successfully to convert ethanol to acetaldehyde. Quantitative conversions of 20-g/L solutions of ethanol have been achieved in 2 h, and acetaldehyde concentrations of up to 35 g/L have been achieved using extended reaction times of 5 h. The conversion reaction was limited by end product inhibition and by acetaldehyde holdup within the yeast cells.
49 citations
TL;DR: Immobilized cells retained more of their activity during repeated batch cycles than did free cells and were more resistant to heat denaturation both in the presence and absence of ethanol.
Abstract: Free and immobilized cells of Pichia pastoris were used to convert ethanol to acetaldehyde in small-scale batch reactors. Immobilized cells were less active than free cells (V(max) free = 7.81 g/L h, V(max) immobilized = 3.17 g/L h) due to a number of factors including end product inhibition and diffusional limitations. Immobilized cells were more resistant to heat denaturation both in the presence and absence of ethanol. Immobilized cells retained more of their activity during repeated batch cycles than did free cells.
25 citations
TL;DR: Benzylamine oxidase (EC 1.4.3) from the yeast Pichia pastoris is a 106 kDa quinoprotein containing one copper atom per molecule as discussed by the authors.
22 citations
01 Jan 1988
21 citations
TL;DR: In order to confirm the chemical structure of the mannan of Pichia pastoris IFO 0948 strain, which was assumed to possess a highly branched comb-like structure, a sequential degradation procedure involving partial acid hydrolysis followed by acetolysis under mild conditions was employed.
Abstract: In order to confirm the chemical structure of the mannan of Pichia pastoris IFO 0948 strain, which was assumed to possess a highly branched comb-like structure, a sequential degradation procedure involving partial acid hydrolysis followed by acetolysis under mild conditions was employed. This procedure can widely be adopted as a method for determining the structural shape of fungal mannans possessing a highly branched structure, either comb-like or tree-like, without application of enzymolytic degradation.
9 citations
Patent•
02 Nov 1988
TL;DR: In this paper, a method of producing at high levels an animal lysozyme c by culturing Pichia pastoris cells, which have a gene capable of expressing the pre-form of the animal pre-szyme c in such cells, under conditions such that the gene is transcribed.
Abstract: The present invention provides a method of producing at high levels an animal lysozyme c by culturing Pichia pastoris cells, which have a gene capable of expressing the pre-form of the animal lysozyme c in such cells, under conditions such that the gene is transcribed. Mature animal lysozyme c is secreted at a high level from such cells into the culture medium, when the cells are cultured under conditions such that the animal pre-lysozyme c gene is transcribed in them. Also provided by the invention are DNAs capable of transforming Pichia pastoris to express animal pre-lysozyme c's, cultures of P. pastoris cells transformed with such DNAs, bovine pre-lysozyme c2, the signal peptide of bovine pre-lysozyme c2, and DNAs encoding those polypeptides.
7 citations