High-lysine corn produced by the combination of enhanced lysine biosynthesis and reduced zein accumulation.

Corn is one of the major crops in the world, but its low lysine content is often problematic for animal consumption. While exogenous lysine supplementation is still the most common solution for today's feed corn, high-lysine corn has been developed through genetic research and biotechnology. Reducing the lysine-poor seed storage proteins, zeins, or expressing a deregulated lysine biosynthetic enzyme, CordapA, has shown increased total lysine or free lysine content in the grains of modified corn plants, respectively.

Improving nutritional quality of maize proteins by expressing sense and antisense zein genes.

The predominant proteins in maize grain are a family of alcohol-soluble prolamin storage proteins called zeins. They account for >50% of total seed proteins but are deficient in several essential amino acids. As a result, the corn grain is considered to be nutritionally poor for monogastric animals with respect to key essential amino acids, most notably lysine, tryptophan, and methionine.

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of zeins in mature maize kernels.

A high-throughput method has been developed to allow rapid analysis of maize seed storage proteins by matrix-assisted laser desorption time-of-flight mass spectrometry. The extraction solution containing an organic solvent, a reducing agent, and a volatile base has been optimized to enable extraction of all classes of zein proteins (alpha-, beta-, gamma-, and delta-). A near-saturating concentration of matrix, 2-(4-hydroxyphenylazo)benzoic acid, was necessary to obtain strong peaks for the most lipophilic zeins, the alpha-zeins.