Transgenic plants cytosol

In transgenic plants, the expression of heterologous proteins can be targeted in different organs, whereas in animals the biological liquids where antibodies can be expressed and then separated are blood and milk. Accumulation in different cellular compartments such as the cytosol, the apoplastic space, and the endoplasmic reticulum are well-described locations where antibodies are expressed.48 A high accumulation of active antibodies was found when targeting the apoplastic space. This has been demonstrated in tobacco seeds and potato tubers.48 The amount of expressed protein compared to the total extractable proteins is also an important information for the purification of antibodies. In corn seeds, for instance, the expressed proteins represent up to about 5% of total extractable proteins.49... 

Harms et al. [197] produced transgenic potato plants overexpressing a flax allene oxide synthase gene. These plants accumulated allene oxide synthase proteins in chloroplasts and accumulated jasmonic acid in levels equivalent to or higher than the wound-induced levels in control plants, but did not accumulate pin 2. The authors speculated that the reason for the lack of pin 2 expression might be involvement of a cytosolic LOX/allene oxide synthase pathway in pin 2 induction or sequestration of jasmonic acid in chloroplasts or peroxisomes in allene oxide synthase transgenic plants, but not wounded plants. Creelman and Mullet [29]... 

Sedbrook, J. C., et al. (1996). Transgenic aequorin reveals organ-specific cytosolic Ca2+ responses to anoxia in Arabidopsis thaliana seedlings. Plant Physiol. Ill 243-257. 

Miao, G.-H., Hirel, B., Marsolier, M.C., Ridge, R.W. Verma, D.P.S. (1991). Ammonia-regulated expression of a soybean gene encoding cytosolic glutamine synthetase in transgenic Lotus corni-culatus. The Plant Cell 3, 11-22. 

Schouten A, Roosien ), van Engelen FA, et al. The C-terminal KDEL sequence increases the expression level of a single-chain antibody designed to be targeted to both the cytosol and the secretory pathway in transgenic tobacco. Plant Mol. Biol., 1996 30(4) 781-793. 

Since the first purification of TDC by Noe et al. (177), this protein has been extensively characterized (178-180). TDC is a cytosolic enzyme (35,39,181-183) and consists of two identical subunits (molecular weights of 54 kDa). It showed Michaelis-Menten kinetics ( , 75 /iM) besides tryptophan, it also accepts 5-hydroxy-, 5-fluoro-, 4-fluoro-, and 5-methyltryptophan as substrates. o-Tryptophan acts as a noncompetitive inhibitor, tryptamine as a competitive inhibitor ( 310 /iM) (177). Pen-nings et al. (179) reported that TDC contains two molecules of pyrroloqui-nolinequinone (PQQ) and two molecules of pyridoxal phosphate. Phenylalanine, tyrosine, and l-DOPA are not accepted as substrates in vitro, but in transgenic tobacco plants carrying the Tdc gene, increased tyramine levels were found (184,185). 

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