Open Letters

More thoughts on folding and form

Maurizio Brunori Arianna Brunori
By Maurizio Brunori and Arianna Brunori
October 28, 2020

We were pleased to read Sudha Neelam’s pleasant and stimulating essay, “The art of paper folding and the science of protein folding,”in ASBMB Today.

Origami-bird-300x161.jpg
Daniel Álvasd/ Unsplash

Outlining the similarity between an origami and a folded protein is quite popular, since in both the form combines beauty and functional relevance. In both cases, the mechanism of folding to achieve the final state is complex. This similarity has been taken further to highlight that a misfolded origami mimics in some way a misfolded protein seen at the onset of neurodegenerative diseases that develop via irreversible population of an amyloid state by extensive misaggregation.

Folding-protein-300x315.jpg
Jawahar Swaminathan/
European Bioinformatics Institute

We should, however, recall one difference between folding a paper sheet and a polypeptide chain, a difference that is of fundamental significance.

The complex course of action to fold a paper sheet to produce origami of a chosen shape demands that precise information be injected in the procedure by an operator (in this specific case, Nihkil, the son of the writer Sudha Neelam). The order of guided steps is essential to overcome the loss of entropy coupled to the creation of an ordered object, such as a classical origami sculpture.

David-300x360.jpg
Jörg Bittner Unna/Wikimedia Commons

In the case of folding a complex 3D structurestarting from one disordered polypeptide, the information guiding the series of events/chemical steps leading to the globular protein is imprinted within the amino acid sequence. The primary structure itself is also the code carrying the instructions on how to fold in water and thereby the information to overcome the huge, unfavorable entropy loss.

In water, the amino acid sequence of a protein conforms beautifully to Aristotle’s definition of substance, the intimate ensemble of matter and form (in Greek: “synolon”), insofar as the amino acid sequence contains in itself the reason for becoming what it is (in Latin: “substantia causa sui”). In this respect, we can compare the amino acid sequence to the marble block as seen by Michelangelo Buonarroti. In Michelangelo’s view, the artist need only bring into actuality the form that already lies in the marble block by chiseling away the superfluous material.

Likewise, as shown by Nobel laureate Christian Anfinsen, the amino acid sequence embeds from the beginning the properties that will characterize the protein in the final functionally competent native state, needing only water to pass from potentiality into actuality.

 

Maurizio Brunori
Maurizio Brunori

Maurizio Brunori is emeritus president of the National Academy of the Lincei and professor emeritus at the Sapienza University of Rome.

Arianna Brunori
Arianna Brunori

Arianna Brunori is a Ph.D. student in medieval philosophy at the Scuola Normale Superiore di Pisa.

Join the ASBMB Today mailing list

Sign up to get updates on articles, interviews and events.

Latest in Opinions

Opinions highlights or most popular articles

The evolution of proteins from mysteries to medicines
Essay

The evolution of proteins from mysteries to medicines

February 27, 2021

An essay in observance of National Protein Day.

Racial stereotypes drive students of color away from STEM
Diversity

Racial stereotypes drive students of color away from STEM

February 13, 2021

But many still persist. Here’s what one researcher has to say about the psychological and physical toll of persistence.

W.E.B. Du Bois embraced science to fight racism
Diversity

W.E.B. Du Bois embraced science to fight racism

February 06, 2021

As editor of the magazine for 24 years, Du Bois featured articles about biology, evolution, archaeology in Africa and more to refute the rampant scientific racism of the early 20th century.

Intense scrutiny of Chinese-born researchers in the US threatens innovation
News

Intense scrutiny of Chinese-born researchers in the US threatens innovation

January 30, 2021

The recent arrest of an MIT engineering professor has once again drawn attention to the role of China in the U.S. science and technology system.

All about Ph.D. committee meetings
Professional Development

All about Ph.D. committee meetings

January 29, 2021

Our academic careers columnist breaks down everything you need to know: What they are, what they’re for, and how to get the most out of them.

Learning to be a science superhero
Essay

Learning to be a science superhero

January 24, 2021

To mark the International Day of Education, Allie Smith looks back on the experiences that shaped their desire to become a scientist and teach others about science.