At the first instance, the scientific accomplishment of getting
egg protein back intact after boiling or unboiling the egg in short might sound
silly and foolish accomplishment. But the seemingly frivolous task of
retrieving protein in its original form is the most daunting task. Protein
biologists struggle with mind boggling and finicky protein extraction protocols
to obtain a functional protein in purest form but the protein becomes unusable
as its gets entangled with itself or gets stuck with the containers and
instruments during experimentation. Thus significant amount of precious protein
is lost. This technique besides revitalising the protein holds the key for
cracking the protein folding problem too. It offers a magical solution for
refolding the proteins into its original shape.
Proteins are quintessential and the most indispensable tools
for working in biological and chemical laboratories. In vivo protein synthesis is
carried out ribosomes dictated by the genetic code. Basically proteins are made
of amino acids that contain carbon, hydrogen, nitrogen, and sulphur oxygen.
Functionality or the efficiency of proteins is determined by the unique nature
of folding of proteins. More often the nature of bonding (hydrophilic –water loving
or hydrophobic- water hating) between the molecules in the protein determines
the shape and activity of the proteins. Proteins in their native state have lowest
energy and are most stable.
Scientists during the course of biological or chemical
research lose significant portion of precious proteins as they get stuck to containers,
instruments or get entangled with each other becoming unusable. Most often
these proteins couldn’t be salvaged easily. Existing techniques are tedious,
time consuming and even the amounts of protein retrieved is too low. Scientists
at the University of Irvine have claimed to have discovered a technique which
can help in untangling the protein and allow them to return to their original
conformation.
Gregory Weiss’s lab using a vortex fluid device untangled
proteins from the boiled egg. The vortex fluid device was used by an Australian
lab to peel sheets of carbon of few atoms thickness from graphene. The device
spins molecules in liquid state and spins them through an open- ended test tube.
The liquid spreads out as a thin layer of few microns (one millionth of meter)
thickness. The forces in the rapidly spinning tube transfer energy to the
molecules, separating them in a controlled way. Weiss contemplated on using the
machine for revitalising proteins. Egg white is watery containing several
proteins besides lysozyme. Upon heating structural bonds between proteins are
broken, thus they lose their native conformation and become a thick clump of solid
mass. Now, scientists tried to recover lysozyme by dissolving the egg white in
a solution that breaks the clumps overnight. After a day the solution becomes
clear, full of unfolded proteins.
Refolding is the biggest task to restore the functionality of
protein. Solution of unfolded proteins is whirled through the vortex fluid
machine wherein proteins spread out as thin layer separated from its neighbour
thus allowing the proteins to refold without tangling. By fine-tuning the speed
and rotation of the vortex, scientists can generate the force strong enough to separate
protein molecules apart from each other and gentle enough to allow them to
refold into their natural shapes. Scientists first used this technique to
restore a protein from Escherichia coli, protein kinase A (PKA) three times
larger than lysozyme. They slightly modified the protocol to refold the
protein. They managed to manipulate the protein into refolding by hinging one
end of protein onto a large bead (Ni+2charged immobilised metal affinity
chromatography). This in fact is similar to the process by which proteins are
folded naturally by the ribosomes.
The force requirement for different protein would vary and
subsequently the protocol should be effectively reconstructed to suit to the
needs. Scientists are now aiming to build a large-scale vortex machine and
exploring the possibility of using different solutions, level of forces and
settings suited for different proteins. This method has the ability to
transform the production of proteins. Pharmaceutical companies have started creating
cancer antibodies in expensive hamster ovary cells which often don’t fold
properly and a misfolded protein is not functional. This technique could be of
great help to pharmaceutical and biotechnology industries that work on
recombinant proteins. It can aid in untangling over expressed proteins that are
jettisoned into inclusion bodies as complex aggregates.
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