The phosphofructokinase (PFK) reaction is a major control point in glycolysis. It is the slowest reaction in glycolysis and is regulated by several molecules, but not by naturally changing concentrations of reactants and products. The molecules mentioned below allosterically regulate PFK activity. Indicate whether each condition described increases or reduces PFK activity (specifically in mammalian liver).

To keep cells alive, ATP production is necessary, the process by which it is produced is glycolysis, one of the most important enzymes in this process is phosphofructokinase (PFK) that performs the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate.

allosteric proteins, such as hemoglobin, contain multisubunit proteins such as phosphofructokinase, which produce a chain reaction by stimulating their units.

In enzymes such as PFK, which contain allosteric particles, their functions can be modified by attaching an activator or inhibitor to their receptor, which when applied will produce a chain reaction of the other subunits, one will activate the next, and so on until it occurs. the desired reaction

The receptor X has changed shape because amino acids with charged or ionic or hydrophilic R-groups were replaced by two amino acids with uncharged or nonpolar or hydrophobic R-groups.

Explanation:

R-groups or side chains attached to the amino acids determine their properties. Polar/hydrophilic R-groups will render the amino acid hydrophilic. It is more likely to interact with polar environments like the extracellular matrix or the cytosol.

Whereas, non-polar/hydrophobic side chains render amino acids hydrophobic. This means that they world orient themselves towards the inside of the protein i.e. the tertiary structure of proteins.

According to the attached image, the original amino acid sequence is Threonine - Lysine - Glutamate - Valine - Glycine, whereas, Threonine - Isoleucine - Alanine - Valine - Glycine is the altered sequence.

You can observe that Lysine and Glutamate are polar amino acids, likely to be present on the surface of the protein. Whereas, isoleucine and alanine are non-polar, likely to be present on the inside. Therefore, this change in the sequence forces a conformational change in the receptor X.