Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


New technique efficiently turns antibodies into highly tuned 'nanobodies'


Antibodies, in charge of recognizing and homing in on molecular targets, are among the most useful tools in biology and medicine. Nanobodies – antibodies' tiny cousins – can do the same tasks, for example marking molecules for research or flagging diseased cells for destruction. But, thanks to their comparative simplicity nanobodies offer the tantalizing prospect of being much easier to produce.

Unfortunately, their promise hasn't been fully realized, because scientists have lacked an efficient way of identifying the nanobodies most closely tuned to their targets. However, a new system, developed by researchers at Rockefeller University and their collaborators and described today in Nature Methods, promises to make nanobodies dramatically more accessible for all kinds of research.

Antibodies are defensive proteins deployed by the immune system to identify and neutralize invaders. But their power can be harnessed in other ways as well, and they are used in biology and medicine for visualizing cellular processes, attacking diseased cells and delivering specific molecules to specific places. Like their larger cousins, nanobodies can also be used for these tasks but their small size makes nanobodies much easier to grow in bacterial factories. They can also access hard to reach places that may be off limits to larger molecules.

"Nanobodies have tremendous potential as versatile and accessible alternatives to conventional antibodies, but unfortunately current techniques present a bottleneck to meeting the demand for them," says study author Michael Rout, head of the Laboratory of Cellular and Structural Biology at Rockefeller. "We hope that our system will make high-affinity nanobodies more available, and open up many new possible uses for them."

... more about:
»GFP »Laboratory »Rockefeller »immune »proteins »sequence

In their first studies, the team generated high-affinity antibodies, those that are capable of most precisely binding to their targets, directed against two fluorescent proteins that biologists often use as markers to visualize activity within cells: GFP and mCherry. Their new system, like existing ones for generating antibodies, begins with an animal, in this case llamas housed in a facility in Connecticut.

Llamas were chosen because the antibody variants they produce are easily modified to generate nanobodies, which are only one-tenth the weight of a regular antibody. The llamas were immunized with GFP and mCherry, prompting their immune systems to generate antibodies against these foreign proteins.

"The key was to figure out a relatively fast way of determining the genetic sequences of the antibodies that bind to the targets with the greatest affinity. Up until now obtaining these high-affinity sequences has been something of a holy grail," says Brian Chait, Camille and Henry Dreyfus Professor and head of the Laboratory of Mass Spectrometry and Gaseous Ion Chemistry at Rockefeller. "Once those sequences are obtained, it's easy to engineer bacteria to mass produce the antibodies."

The researchers, led by graduate student Peter Fridy and postdoc Yinyin Li, started by making antibody sequence databases from RNA isolated out of antibody-producing cells in the llamas' bone marrow. Next, they picked out the tightest binding GFP and mCherry antibodies from blood samples from the same llamas, and chemically cut these into smaller pieces, keeping only the antigen-binding section to create nanobodies.

They then determined partial sequences of the amino acids that made up the protein of the nanobodies with a technique known as mass spectrometry. Using a computer algorithm called "llama magic," developed by David Fenyö and Sarah Keegan of New York University School of Medicine, they matched up the composition of the highest affinity nanobodies with the original RNA sequence. With this sequence, they could engineer bacteria to mass produce the nanobodies before putting them to use in experiments.

Antibodies are often used to isolate a particular structure within a cell so scientists can remove and examine it, and the team did just that with their new nanobodies. They purified various cellular structures tagged with GFP or mCherry, and also visualized these structures in situ.

All in all, their procedure generated 25 types of nanobodies capable of precisely targeting GFP and six for mCherry, a far more diverse set of high affinity nanobodies than is typically possible with conventional techniques.

This abundance opens up new options. Scientists can select only the best ones, eliminating nanobodies that by chance cross-react with other molecules, or string together two nanobodies that attach to different spots on the same target molecule to generate a super-high-affinity dimer, exactly as the researchers demonstrated for the GFP nanobodies. This super-high-affinity could be a powerful feature when delivering therapeutic or diagnostic molecules because it would lower the required dosage, and so reduce unwanted side effects.

"Given that we can now readily identify suites of high affinity nanobodies, the future for them as research tools, diagnostics and therapeutics looks bright," says Rout.

Zach Veilleux | EurekAlert!
Further information:

Further reports about: GFP Laboratory Rockefeller immune proteins sequence

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>