The synthesis of L-tryptophan degrading bioreactors.

Abstract

To design a bioreactor for removing the potential cancer nutrient L-tryptophan from blood, the L-tryptophan degrading enzyme tryptophan side chain oxidase (TSO) was chemically bound to glutaraldehyde activated gamma amino silane silica and to Zetaffinity microcolumns consisting of a glutaraldehyde activated polyacrylic-cellulose copolymer. Five experiments were carried out in sheep and six experiments in rabbits using a closed circuit plasmapheresis bioreactor system. L-tryptophan in sheep was degraded by the silica bioreactor in a single pass to undetectable levels as measured by high performance liquid chromatography (HPLC). Zetaffinity bioreactors degraded L-tryptophan in rabbits to more than 95% in a single pass. Whole blood L-tryptophan levels changed little throughout the experiment indicating a vast extravascular tryptophan pool. Enzyme leakage from the bioreactor was less than 10(-5) IU TSO per ml plasma. The procedures were tolerated well by the animals without any change in vital signs.

• Authors: G Schmer, M B Dennis, S Hsueh, K C Hou
• Journal: The International journal of artificial organs (Int J Artif Organs) Vol. 13 Issue 5 Pg. 316-20 (May 1990) ISSN: 0391-3988 [Print] United States
• PMID: 2163986 (Publication Type: Journal Article)

Chemical References

• Silicon Dioxide
• Tryptophan
• Mixed Function Oxygenases
• indolyl-3-alkane-alpha-hydroxylase
• Glutaral

Topics

• Animals
• Glutaral
• Mixed Function Oxygenases (metabolism)
• Plasmapheresis (methods)
• Rabbits
• Sheep
• Silicon Dioxide
• Tryptophan (blood, metabolism)