In recent years, scientists have created music based on the structure of proteins as a creative way to better popularize science to the general public, but the resulting songs haven't always been pleasant to the ear.
In a new study published in the journal Heliyon on September 29, researchers from the National University of Singapore sought to address this problem.
Existing protein music has mostly been designed by simple mapping of certain amino acid patterns to fundamental musical features such as pitches and note lengths, but they do not map well to more complex musical features such as rhythm and harmony.
To solve this problem, the research team analyzed the pitch, length, octaves, chords, dynamics, and main theme of four pieces from the mid-1800s Romantic era of classical music.
These pieces, including Fantasie-Impromptu and Wanderer Fantasy from Chopin and Franz Schubert, were selected to represent the notable genre that emerged during that time.
"We chose the specific music style of a Fantasy-Impromptu as it is characterized by freedom of expression, which we felt would complement how proteins regulate much of our bodily functions, including our moods," co-author Peng Zhang said in a report posted by Cell Press.
Likewise, several of the proteins in the study were chosen for their similarities to the key attributes of the Fantasy-Impromptu style. Most of the 18 proteins tested regulate functions including human emotion, cognition, sensation, or performance which the authors say connect to the emotional and expressive of the genre.
Then, they mapped 104 structural, physicochemical, and binding amino acid properties of those proteins to the six musical features.
"We screened the quantitative profile of each amino acid property against the quantized values of the different musical features to find the optimal mapped pairings. For example, we mapped the size of amino acid to note length, so that having a larger amino acid size corresponds to a shorter note length," says Chen.
Across all the proteins tested, the researchers found that the musicality of the proteins was significantly improved. In particular, the protein receptor for oxytocin (OXTR) (responsible for love, satisfaction, trust, and intimacy) was judged to have one of the greatest increases in musicality when using the genre-guided algorithm, compared to an earlier version of the protein-to-music algorithm.