Process development and economic evaluation of recombinant human lactoferrin expressed in rice grain.
In this paper, we show that recombinant human lactoferrin (rhLF) has been stably expressed at 0.5% brown rice flour weight for nine generations. Process development indicates that rhLF can be efficiently extracted from rice flour in 20 mM phosphate buffer (pH 7.0) containing up to 0.5 M NaCl and at a ratio of 1 kg flour to 10 L buffer. After solid/liquid separation, the extract can then be loaded directly onto an ion-exchange column and rhLF can be eluted using 0.8 M NaCl. The resulting rhLF is about 95% pure. A range of biochemical and biophysical analyses were carried out and results indicated that the purified rhLF was identical to its native human counterpart other than its glycosylation. Economic analysis shows that at 600 kg/year scale, the cash cost to produce 1 g of rhLF of pharmaceutical grade is US$ 5.90. Analysis also indicates that the expression level has profound impact on costs related to planting, milling, extraction and purification, thus high level expression of recombinant protein in plants is one of the key parameters for the success of plant made pharmaceuticals.
Nandi
Somen
S
Ventria Bioscience, 4110 North Freeway, Sacramento, CA 95834, USA.
Yalda
Dorice
D
Lu
Stephen
S
Nikolov
Zivko
Z
Misaki
Ryo
R
Fujiyama
Kazuhito
K
Huang
Ning
N
D001709:Biotechnology / Q000191:economics*; D002352:Carrier Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D002852:Chromatography, Ion Exchange; D005433:Flour; D030841:Food, Genetically Modified / Q000191:economics; D006801:Humans; D007781:Lactoferrin; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D004364:Pharmaceutical Preparations / Q000191:economics; D030821:Plants, Genetically Modified / Q000378:metabolism; D011994:Recombinant Proteins / Q000191:economics / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012639:Seeds / Q000235:genetics* / Q000378:metabolism; D012965:Sodium Chloride; D013696:Temperature
D002352:Carrier Proteins; C490098:LTF protein, human; D004364:Pharmaceutical Preparations; D011994:Recombinant Proteins; D012965:Sodium Chloride; D007781:Lactoferrin