Enhancement of essential amino acid contents in crops by genetic engineering and protein design

Abstract

Summary The importance and urgency of providing humans and animals with quality proteins are reflected in the growing scientific and industrial interest in augmenting the nutritive value of the world's protein sources. Such nutritive value is determined by the protein content in ‘essential amino acids’, those that cannot be synthesized de novo and that must be supplied from the diet. It is the object of this review to discuss recent advances in the genetic modification of crops that aim to provide enhanced quantities of essential amino acids.

Fortifying plants with the essential amino acids lysine and methionine to improve nutritional quality

“…The researchers have tested four different strategies as described below: Expressing recombinant genes encoding synthetic proteins with higher proportions of Met and/or Lys. Although significant efforts were invested in designing synthetic genes encoding proteins rich in Met and/or Lys, this strategy faced major difficulties associated with protein stability, digestibility and toxicity (for review, see Beauregard and Hefford, ; Wenefrida et al ., ). Expressing recombinant genes encoding seed storage proteins fortified with additional codons for these two essential amino acids. This strategy emerged with the idea to use genes encoding seed storage proteins that accumulate to high levels in seeds and enrich them with codons for Lys and/or Met.…”

In silico Designing of Protein Rich in Large Neutral Amino Acids Using Bovine αs1 Casein for Treatment of Phenylketonuria

“…Protein designing has been extensively used to increase the essential amino acid contents in proteins for the enhancement of its nutritional quality [10]. Protein designing can be performed by homology modeling, which predicts the 3D structure of the target protein based on its alignment to the template whose structure has already been experimentally determined [11].…”

Seed-Specific Expression of a Lysine-Rich Protein Gene, GhLRP, from Cotton Significantly Increases the Lysine Content in Maize Seeds

“…Essential amino acids are necessary for good health, but must be obtained from the diet, because humans and monogastric animals cannot synthesize them. Consuming a protein-deficient diet over the long term may lead to poor growth, disease and, in severe cases, death [2,3]. Therefore, improving the composition of maize proteins is highly desirable.…”