Plasma Protein Levitation Technique Could Provide New Diagnostic Tool

Researchers at Michigan State University have developed a technique to levitate plasma proteins using a magnetic field. The technique provides very accurate information on the density of the proteins, and could reveal signatures of disease, potentially allowing clinicians to diagnose various conditions, such as multiple sclerosis, more easily.

The technique involves mixing a sample of plasma proteins with magnetic nanoparticles and then applying a magnetic field to separate different proteins into discernible bands. “When we put something in liquid, it separates into sediment by weight,” said Morteza Mahmoudi, a researcher involved in the study. “But another force – the magnetic force – can cancel out weight and levitate the proteins. This permits us to much more precisely define the density of proteins in solution.”

Plasma proteins play a variety of roles in normal physiological processes, as well as in disease. For instance, antibodies are involved in immunity and auto-immune diseases, and lipoproteins are important for transporting fats and also play a role in cardiovascular disease. Understanding the fundamental properties of such proteins, including their density, can provide important information about their role in disease. At present, accurately measuring plasma protein density is difficult.

This new magnetic levitation technique appears to provide very accurate protein density data. “The findings are of crucial importance, as protein density is being used to define proteins’ physical properties, including their 3D structures,” said Mahmoudi. “In addition, the accurate density of proteins enables us to design safer and more efficient therapeutic agents, such as nanomedicine.”

The researchers believe that the plasma protein bands created through magnetic levitation could provide a signature of various diseases. In a recently published study, they compared the plasma of healthy volunteers with that from people who abuse opioids, and found a distinctive pattern in the plasma proteins of the opioid group, whereby the opioid abusers had higher levels of certain types of hemoglobin.

Now the researchers are moving toward trying to find levitated protein signatures for diseases, such as multiple sclerosis and cancer. “There are four subtypes of MS, but diagnosis is currently based on the patient’s behavior, symptoms, and his or her response to treatment,” said Mahmoudi. “There is no biomarker or MRI test to diagnose the different subtypes at the early stages. Correctly diagnosing the type of MS is critical, since it dictates which type of treatment is appropriate. We hope this MagLev method will give clinicians a technique to define the subtypes.”

Study in Analytical Chemistry: Magnetically Levitated Plasma Proteins

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