Neuroscience

What happens in the bodies of ALS patients?

Amyotrophic lateral sclerosis (ALS) is an incurable disease of the central nervous system. In most cases, ALS is fatal within a short period following diagnosis. However, people sometimes live with the disease for decades, ...

Medical research

Sweetening the deal on bone repair

By replacing or replenishing injured tissue with biomimetic structures, scientists can help initiate stem cell-driven repair cascades throughout the body. Insights from an A*STAR-led study of the interactions between bone ...

Neuroscience

Concussion-related biomarkers vary based on sex, race

(HealthDay)—Concussion-related serum biomarkers vary by sex and race, which may complicate their interpretation, according to three studies published online Nov. 7 in Neurology.

Immunology

How our immune system detects broken DNA

Our immune system is working every day to protect us from bacteria, viruses, and parasites, but it can also detect when our own cells are damaged.

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Carrier protein

Carrier proteins are proteins that transport a specific substance or group of substances through intracellular compartments or in extracellular fluids (e.g. in the blood) or else across the cell membrane. Some of the carriers are water-soluble proteins that may or may not interact with biological membranes, such as some transporters of small hydrophobic molecules, whereas others are integral transmembrane proteins.

Carrier proteins transport substances out of or into the cell by facilitated diffusion and active transport. Each carrier protein is designed to recognize only one substance or one group of very similar substances. The molecule or ion to be transported (the substrate) must first bind at a binding site at the carrier molecule, with a certain binding affinity. Following binding, and while the binding site is facing, say, outwards, the carrier will capture or occlude (take in and retain) the substrate within its molecular structure and cause an internal translocation, so that it now faces the other side of the membrane. The substrate is finally released at that site, according to its binding affinity there. All steps are reversible.

For example:

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