Comparative field performance over 3 years and two sites of transgenic wheat lines expressing HMW subunit transgenes.

A series of transgenic wheat lines expressing additional high molecular weight (HMW) subunit genes and the corresponding control lines were grown in replicate field trials at two UK sites (Rothamsted Research, approximately 50 km north of London and Long Ashton, near Bristol) over 3 years (1998, 1999, 2000), with successive generations of the transgenic lines (T3, T4, T5) being planted. Four plots from each site were used to determine grain dry weight, grain nitrogen, dough strength (measured as peak resistance by Mixograph analysis) and the expression levels of the endogenous and "added" subunits. Detailed statistical analyses showed that the transgenic and non-transgenic lines did not differ in terms of stability of HMW subunit gene expression or in stability of grain nitrogen, dry weight or dough strength, either between the 3 years or between sites and plots.

Characterization of the emulsification properties of 2S albumins from sunflower seed.

The ability of 2S albumins from sunflower seeds to stabilize oil-in-water emulsions has been investigated, demonstrating that one of the proteins (SFA8) effectively stabilizes emulsions, while another (SF-LTP) does not stabilize emulsions. The surface tension and surface dilation viscosity of these two proteins were measured, rationalizing the emulsifying ability of SFA8 in terms of its ability to form a strongly elastic monolayer at interfaces. The secondary structure changes that occur upon adsorption of SFA8 to the oil/water interface have also been studied by fluorescence, circular dichroism (CD), and Fourier-transform infrared (FT-IR) spectroscopy.

The expression and processing of two recombinant 2S albumins from soybean (Glycine max) in the yeast Pichia pastoris.

Soybean seeds contain two 2S albumin storage proteins (AL1 and AL3) which may contribute to their industrial processing quality and allergenicity. We show that these proteins (AL1 and AL3) are well expressed by the methylotrophic yeast Pichia pastoris and that one of the secreted proteins (AL3) has a similar conformation and stability to that purified from soybean seeds. Further, we show that the subunits are post-translationally processed within the same loop region as the native protein but with some differences in the precise sites.