1. How Ligands Bind to Cell Receptors

A cell receptor consists of two parts, both of which must be compatible with a given ligand for a full binding.

2. What are Consonance and Dissonance?

A ligand may only be compatible with one of the two receptor parts, while the other part remains incompatible with the ligand.

  • In music, the relationship between two tones (an interval) is either consonant or dissonant.

  • Like ligands binding with cell receptors, they refer to the differing levels of compatibility between any two tones.

 When an interval is consonant, it has a pleasant,
 “finished” sounding quality.

 When an interval is dissonant, it sounds uglier,
 as though it needs to be “resolved” to something 

3. Using Intervals to Represent Ligand Bindings

We use two tones (an interval) to represent the two parts of the cell receptor, and a seperate single tone to represent a ligand.

The ligand tone will match the continuous rhythm of the receptor tones to represent a binding. Other ligand tones will be present, but will not attempt to bind to the receptor- they are playing separate, erratic rhythms.

4. Examples of Intervals Used: Consonant

To represent a fully compatible binding, we used a perfect 5th interval for the two receptor parts, with the 3rd between them representing the ligand.

This makes a consonant major triad.

5. Examples of Intervals Used: Dissonant

To represent an incompatible binding, we used the same interval to represent the receptors, but this time a **2nd** between the receptor notes represents the ligand.

This note sounds dissonant with each of the two receptor notes separately, producing a minor 2nd and a tritone.

6. Intervals: A major 3rd plus a minor 2nd

To represent a partially compatible binding, we used a **perfect 4th** interval (simply 4 notes apart instead of 5, as used previously) to represent the cell receptor.

The two tones are B-flat and E-flat.
 There are two examples of partially compatible bindings. First, we inserted a D between the tones- this is consonant with one of the two receptor notes (the B-flat, producing a major 3rd) and dissonant with the other (the E-flat, producing a minor 2nd).

7. Intervals Used: major 3rd + minor 2nd

For the second example of a partially compatible binding, we inserted a different note between the same B-flat and E-flat.

This new note, a C-flat, is consonant with the E-flat (producing a major 3rd) but dissonant with the B-flat (producing a minor 2nd.) The consonant and dissonant intervals are the same in each partially compatible binding, but the compatible receptor has changed.

8. What Purpose Does a Ligand Binding Serve?

When multiple ligands bind to a cell’s receptors at the same time, they can bring about behavioral changes in the cell.

We chose to show this with a pair of bindings, represented by chords, evolving into a chord progression (then, a full piece of music!)
 If a ligand is incompatible or only partially compatible with a certain receptor pair, the cell’s behavior will be unaffected. Thus, a cell will change the nature of its receptors to match the ligand attempting to bind. This is represented by the receptor tones changing to become consonant with the original ligand tone.

9. Steps Toward Music

  • Receptor 1: Fully compatible binding (consonant intervals)

  • Receptor 2: Incompatible binding (dissonant intervals)

Receptor 2 changes its two tones to become consonant with the original ligand tone which attempted to bind to it.
Once multiple receptors have achieved full compatibility, a larger and more complex consonant chord is achieved, which gives way to an improvisation- something spontaneous, just as a cell may spontaneously be able to change its behavioral abilities.

10. Example I:

Fully Compatible Binding
  • C and G = Cell Receptors

  • E = Binding Ligand

11. Example II:

Incompatible Binding
  • C and G = Cell Receptors

  • D-Flat = Binding Ligand

12. Example III:

Partially-Compatible Binding A
  • B-flat and E-flat: Cell Receptors

  • D: Binding Ligand (consonant with B-flat, dissonant with E-flat)

13. Example IV:

Partially-Compatible Binding B
  • B-flat and E-flat: Cell Receptors

  • C-flat: Binding Ligand (consonant with E-flat, dissonant with B-flat)

14. Example V part I:

Multiple Receptors and Ligands Binding at Once

Receptor I: Compatible Binding

Compatible Binding

Receptor II: Incompatible Binding which becomes compatible

Incompatible Binding

15. How Ligands Bind to Cell Receptors

A chord progression!

The full chord produced by multiple compatible bindings occuring at once can spontaneously become a chord progression!