Washington, May 13 : American scientists have shown that a new kind of genetically modified yeast cell can produce complex proteins up to 300 times more than was possible in the past.

The "super yeast" may help boost production and lower prices of a new generation of protein-based drugs for fighting diabetes, obesity, and other diseases.

Lei Wang and Qian Wang of the Salk Institute for Biological Studies say that the yeasts are intended for speeding production of proteins containing so-called "unnatural amino acids" (UAAs).

In their study report, appearing in the Journal of the American Chemical Society, the researchers say that living things normally use the same basic set of 20 amino acids to make proteins.

Scientists have made additional amino acids, the UAAs, which show promise for building new proteins with a broad range of medical and industrial applications.

However, they have faced a lot of difficulty in efficiently incorporating such UAAs into useful protein products.

The Salk researchers say that they have a solution to that problem.

During their study, the researchers inserted parts of the simple but highly efficient protein-making machinery of E. coli bacteria into the advanced but inefficient protein-making machinery of yeast cells.

It resulted in a genetically-engineered yeast cell that produces complex proteins containing UAAs at levels 300 times higher than normal yeast cells, they said.