By Katherine Bagley
From Scientist
Researchers have identified a role for rare, right-handed versions of amino acids. This so-called D-form of nature's building blocks allows bacterial cell walls to adapt to changes in the environment, says a study in Science this week--marking one of the few times the D-aminos have been linked to biological function.
"If you go back in literature dating 20-40 years ago, it was widely believed that we existed in a strictly 'left-handed' protein world," said Steven R. Blanke, a microbiologist at the University of Illinois who was not involved in the study. The current work and a few other recent studies, he said, show that "some biological systems could have possibly evolved to utilize the D-forms of some amino acids more than previously thought."
Nineteen of the 20 amino acids found in nature come in two forms, mirror images in structural composition, but until recently it seemed life on Earth used only one of them. L-amino acids were viewed as the building blocks of life, leaving researchers perplexed as to the function of their D-amino siblings. Over the past 20 years, though, studies have gradually begun to identify important roles for D-amino acids as, for example, key components of antibiotics, immunosuppressive drugs, and antitumor agents, and as neurotransmitters in the brain.
Read full article.
