Washington: In what could help "build"
new biological systems in the future, scientists claim to have
created for the first time artificial proteins that enable the
growth of living cells.
A team at Princeton University has constructed genetic
sequences never before seen in nature and showed that they can
produce substances which sustain life in cells as readily as
proteins produced by nature`s own toolkit.
"What we`ve here are molecular machines that function
quite well within a living organism even though they were
designed from scratch and expressed from artificial genes.
"This tells us that the molecular parts kit for
life need not be limited to parts -- genes and proteins --
that already exist in nature," said Prof Michael Hecht, who
led the research.
He added: "Our work suggests that the construction
of artificial genomes capable of sustaining cell life may be
Nearly all previous work in synthetic biology has
focused on reorganising parts drawn from natural organisms.
In contrast, the results described by the team show
that biological functions can be provided by macromolecules
that were not borrowed from nature, but designed in the
laboratory, says Hecht. Although scientists have shown previously that
proteins can be designed to fold and, in some cases, catalyse
reactions, the Princeton team`s work represents a new frontier
in creating these synthetic proteins.
For their research, Hecht and the students in his
lab study the relationship between biological processes on the
molecular scale and processes at work on a larger magnitude.
Proteins are the workhorses of organisms, produced
from instructions encoded into cellular DNA. The identity of
any given protein is dictated by a unique sequence of 20
chemicals known as amino acids. If the different amino acids
can be viewed as letters of an alphabet, each protein sequence
constitutes its own unique "sentence."
The team set about to create artificial proteins
encoded by genetic sequences not seen in nature. They produced
about 1 million amino acid sequences that were designed to
fold into stable three-dimensional structures.
"What I believe is most intriguing about our work is
that the information encoded in these artificial genes is
completely novel -- it does not come from, nor is it related
to, information encoded by natural genes, and yet the end
result is a living, functional microbe," said team member
The findings have been published in the `PLoS ONE`