Medicus curat natura sanat, in this Latin proverb is clearly underlined the fact that in the nature can be found the cure or the solution even for the most dangerous diseases.

In the fruit of the banana, Musa acuminata and Musa balbisiana is isolated BanLec – Banana Lectin.

Lectins are proteins that bind carbohydrates and serve in a wide variety of cell-cell recognition, signaling and adhesion processes.

BanLec is a homodimer of two identical subunits and this protein is very stable, unfolding only at high temperatures.

BanLec functions as a “T-cell mitogen”, which means that this protein stimulates T-cell division upon binding on them. The interesting fact is that certain viruses like HIV, hepatitis C also contain similar sugar molecules on their surface where BanLec grasps onto them. This interaction acts as a barrier to cell entry and the virus can’t penetrate the cell and steal the host’s machinery to replicate.

The problem that was presented with BanLec is that stimulating the immune cells to proliferate in the presence of infection can lead to systemic inflammation and worsens the infection because it provides the virus a greater pool of cells to infect.

Based on these fact scientist decided to modify the structure of BanLec to see if they can separate the mitogenic and antiviral effects of this molecule. The group of researchers demonstrated that replacing Histidine 84 with a threonine significantly reduces the mitogenic effect of BanLec, while preserving its antiviral potency.

When the team tested this novel molecule in vitro they found that was able to prevent not only HIV from penetrating cells, but also hepatitis C and influenza viruses.

The major advantage of designer lectins lies in the fact that the risk of resistance is low because glycan’s cannot be modified as easily as protein structures.

Further studies with greater impact need to prove the fact if this molecule is safe or effective in humans and then hopefully it can be used as a therapy.

References:

  • Image adapted from: www.uofmhealth.org/sites/default/files/banana%20lectinsm.png.
  • http://www.iflscience.com/health-and-medicine/banana-molecule-fights-hiv-and-hepatitis-c
  • http://www.cell.com/cell/abstract/S0092-8674(15)01273-
  • https://en.wikipedia.org/wiki/BanLec
  • Lehninger Principles of Biochemistry, 6th edition. P269

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