Posted: October 20, 2008

Magnetic tweezer for cells and molecules

(Nanowerk News) Life, on the microscopic level, is crowded and bustling. Tissues are made of cells glommed together that are covered with molecules. The molecules are constantly interacting with other molecules, and how they interact can mean the difference between good health and disease or life and death.
Some of the greatest insights biologists have come from teasing apart the tiny interactions that underlie it all. Now Gil Lee and colleagues at University College in Dublin, Ireland have developed a new way to tweeze apart interacting cells and molecules using magnetic forces. This technology, which relies on attaching microscopic magnetic particles, allows them to measure exactly how strongly the interactions are between biological molecules. They can do this sensitively enough to be able to measure the "bond strength" with which two individual molecules are held together. Bond strength is one of the most important features of molecular interactions because it determines how strongly or weakly molecules in the human body interact-or if they interact at all.
Recently Lee and his colleagues looked at one of the classic pairs of interacting molecules, the protein immunoglobin G, which plays a critical role in the immune system by recognizing pieces of foreign pathogens. Interestingly they saw two types of bonds. One was strong while the other much weaker. They are now expanding this work to look at whole cells and developing the technology as a way to screen particles.
"Magnetic Tweezers Measurement of the Bond Lifetime-Force Behavior of the IgG-Protein A Specific Molecular Interaction" will be at 9:00 a.m. on Wednesday October 22, 2008, in Room 202 of the Hynes Convention Center.
Source: American Institute of Physics
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