Question

Is it possible (or meaningful) to count how many proteins (protein copy number?) of a certain type a given cell has on its surface?

For instance, say there is some membrane integral protein X. Is it possible to take a population of cells, and arrive at a number (say 100) that reflects the average number of X per cell in the population?

I'm trying to look for publications that have done something along these lines, and I've had no luck so far. This made me wonder if this is even a meaningful idea at all, so I decided to see clarification here. (Apologies if this is a trivial question.)

Answer 1

Counting the number of specific membrane proteins on a cell's surface is possible using techniques such as flow cytometry and fluorescent tagging, and provides valuable information about the protein's function.

Step-by-step explanation:

Yes, it is both possible and meaningful to count the number of proteins of a certain type on a cell's surface, and the process typically involves methods from the fields of biochemistry and cell biology. To estimate the average number of a specific integral membrane protein per cell in a population, techniques like flow cytometry or fluorescent antibody tagging can be used. These methods rely on the ability to label the proteins with a dye or fluorescent tag and then count them under specific conditions. The average number of proteins per cell can then be extrapolated from the intensity of fluorescence or the number of tagged particles detected. This data is invaluable in understanding the function and regulation of proteins within the plasma membrane, including their roles in transport, signaling, and cellular interaction.