BEIJING, Dec. 6 (Xinhuanet) -- Researchers at the
U.S. Naval Research Laboratory think they may be able to use llama, camel and
shark antibodies as warnings of biological attacks by terrorists.
"We're interested in the
development of biosensors for biothreats in the field, and hopefully these antibodies
will help lead to more rugged antibodies that have longer shelf lives and not
require refrigeration," explained biochemist Ellen Goldman.
An antibody is a complex protein custom
made to attach to a specific target. Immune cells in the blood and lymph
use antibodies either to identify enemies for attacks or to directly bind to and
neutralize intruders.
Scientists already develop antibodies for use in
medicines against cancers and other diseases or in sensors to warn of dangerous
microbes and chemicals. Unfortunately, high temperatures break down the
antibodies, limiting extended use in the field.
Llama, camel and shark antibodies consist only
of chains of heavy proteins. They don't have the additional lighter protein
chains that more complicated antibodies from other species use. Their relative
simplicity makes them stronger and more capable of withstanding temperatures of
almost 200 degrees Fahrenheit.
Goldman and virologist Andrew Hayhurst at the
Southwest Foundation for Biomedical Research and their colleagues investigated
llama antibodies. Past studies revealed that the binding regions of these
antibodies and those from camels and sharks are unusually small, just one-tenth
the size of common human antibodies.
The researchers generated more than a billion kinds
of antibody binding regions in the laboratory based on genes taken from small
blood samples from llamas.
After testing their antibodies against various
biological threats, the researchers found they could successfully identify
antibodies targeting cholera toxin, a smallpox virus surrogate and ricin within
days.
The researchers wrote they could advance their
technology to isolate useful antibodies against emerging threats within hours.
Goldman added that while the antibodies they have tested successfully bind to
their targets, they hope to develop antibodies that bind more strongly.
The findings are scheduled to be detailed in the Dec.
14 issue of the journal Analytical Chemistry.
(Agencies)
