Protein engineering: Methodology, applications and status

A TIM barrel protein without enzymatic activity? Crystal-structure of narbonin at 1.8 A resolution

The major protein component in seeds is storage protein. These have no known enzymatic activity and act to provide amino acids as a source of metabolites in the developing seedling. We report here the first three dimensional crystal structure of a seed storage globulin at high resolution. The molecule of the 2S globulin, narbonin, from Vicia narbonensis L., consists of an eight-stranded parallel alpha/beta barrel structure similar to that observed in triose phosphate isomerase (TIM). Narbonin is the first protein with this topology possessing no known enzymatic activity. Because of the lack of sequence information most of the primary structure was determined directly from the electron density.

[Recent developments in selected areas of food biotechnology]

With respect to literature and own experiments a review is given of the current international knowledge in special fields of food biotechnology. In this context nutritionally and physiologically relevant problems find particular consideration. After an introduction the development in technology, genetic engineering and protein technology is discussed. Then the following topics are dealt with: Single cell proteins (mushrooms, yeasts, bacteria, fungi, phototrophic microorganisms), soluble enzymes, enzyme inhibitors, immobilized systems (enzymes, cells, new processes and products), amino acids, sweeteners, microbial polysaccharides as hydrocolloids, organic edible acids, plant cell and tissue cultures and flavourings (enzymes, microorganisms, plant systems).