Cancer detection is a major public health challenge, and the methods currently available to achieve it, for example MRIs and mammograms, are often expensive and invasive. This limits their large-scale use. To bypass these constraints, alternative methods are being studied, like the use of a ... more
Hepatitis: 3D structure determination of the ‘gateway’ to the liver
Though an essential gateway to the liver, NTCP had not been well described until now. Na+-taurocholate co-transporting polypeptide (NTCP) is a protein located exclusively in the membrane of liver cells that enables recycling of bile acid molecules. It is also the cellular receptor of human hepatitis B and D viruses (HBV/HDV). A better understanding of NTCP could enable the development of treatments specifically designed for the liver, and to fight HBV and HDV infection.
NTCP is a difficult protein to study. It weighs only 38 kilodaltons (kDa), whereas cryo-electron microscopy, the technology used to study this type of molecule, only works for molecules weighing more than 50 kDA. The challenge was therefore to “enlarge” and stabilise it.
To do this, teams from French and Belgian laboratories developed and tested a collection of antibody fragments targeting NTCP. The 3D structures of the resulting complexes were determined using cryo-electron microscopy, and different antibody fragments stabilised and revealed several forms of NTCP.
The research team was able to describe two essential NTCP conformations: one in which the protein opens a large membrane pore to bile salts, to which HBV and HDV can bind, and a second, ‘closed’ conformation, that prevents recognition by the viruses.
The first, ‘open’ conformation is very surprising, as no other known molecular transporter forms such a ‘wide open’ pore. In turn, the second conformation could help finding antiviral molecules that prevent HBV and HDV infection. The research team intends to continue its work to fully elucidate the functioning of NTCP.
- Na+-taurocholate co…
- hepatitis B
- hepatitis D
- cryo-electron microscopy
Asymmetry plays a major role in biology at every scale: think of DNA spirals, the fact that the human heart is positioned on the left, our preference to use our left or right hand ... A team from the Institute of biology Valrose (CNRS/Inserm/Université Côte d'Azur), in collaboration with co ... more
Magnetic resonance imaging (MRI) has emerged as one of the most powerful clinical imaging tools because of its superb spatial resolution and soft tissue contrast, especially when using contrast agents. In the European Journal of Inorganic Chemistry, scientists have presented a new kind of n ... more
- 1Smartphone-powered microchip for at-home medical diagnostic testing developed
- 2Measuring the ‘wettability’ of graphene and other 2D materials
- 3New method revolutionizes cancer diagnosis
- 4analytica 2022: Analytics that benefit consumer and environmental protection
- 5New technique shows in detail where drug molecules hit their targets in the body
- 6Bruker and TOFWERK Form Strategic Partnership
- 7Researchers demonstrate label-free super-resolution microscopy
- 8A sharper image for proteins
- 9Nanotechnology enables visualization of RNA structures at near-atomic resolution
- 10Why are neuron axons long and spindly?