RESEARCH: INFLUENZA
FOLDING PROJECT #18481 PROFILE

Miniproteins are small proteins designed to fight diseases. Scientists are using computer simulations to understand how these miniproteins bind to a virus protein called hemagglutinin. They want to learn how changes to the miniprotein's design affect its ability to bind and potentially develop better treatments.

Note: This TLDR is a simplication and may not be 100% accurate.

Designed miniproteins are a class of biomolecules with intermediate sizes—larger than small-molecule drugs, but smaller than monoclonal antibodies.

Miniproteins can be computationally designed to tightly bind protein targets for use as potential therapeutics, a promising new avenue for treating infectious disease. Hemagglutinin is a viral fusion protein that allows H1 influenza A (HA) to bind sialic acid on cell surfaces, as well as being involved in the post-endocytosis mechanism of cellular infection.

The Baker lab at University of Washington has developed de novo designed miniproteins that bind hemagglutinin, and improved their binding through affinity maturation (Chevalier et al.

2017).

Many of the mutations seen in affinity-matured sequences are not found in the binding interface, and it remains an open question how these changes lead to higher affinity.

Furthermore, many of the computational predictions of how single-point mutations affect binding deviate significantly from the experimentally determined values. Could all-atom molecular simulation approaches achieve more accurate predictions? In this set of simulations, we aim to use massively parallel expanded ensemble simulations to predict mutational effects on affinities to hemagglutinin.

By pairing these simulations with other simulations aimed at modeling the binding reactions of these miniproteins to hemagglutinin, we aim to have a relatively complete picture of a miniprotein-target binding reaction and how mutations affect it.

These studies are a large-scale investigation on how miniprotein binding reactions work in atomic detail, towards a better understanding of computational design and modulation of miniprotein therapeutics.

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miniproteins

Small proteins designed for therapeutic use.

Miniproteins are small, engineered proteins used as potential medicines. They are smaller than traditional antibodies but larger than small-molecule drugs. Researchers can design miniproteins to bind specific targets in the body, like viruses or disease-causing proteins, potentially treating various conditions.

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therapeutics

Substances used to treat or prevent diseases.

Therapeutics are medications or treatments designed to combat diseases and improve health. This broad category includes various types of drugs, from small molecules to large biologics like antibodies, each targeting specific disease pathways.

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hemagglutinin

A viral protein that binds to sialic acid on cell surfaces.

Hemagglutinin is a crucial protein found on the surface of influenza viruses. It allows the virus to attach to and enter human cells by binding to sialic acid, a sugar molecule present on cell surfaces. Understanding hemagglutinin's structure and function is essential for developing effective influenza vaccines and antiviral drugs.

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affinity maturation

The process of improving the binding affinity of antibodies or other proteins.

Affinity maturation is a natural process where immune systems refine antibody responses. It involves introducing mutations in antibody genes, leading to variations with increased binding strength to target antigens. This process is also harnessed in laboratory settings to develop more potent therapeutic antibodies.

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molecular simulation

Computer-based modeling of molecular behavior.

Molecular simulations use mathematical models to mimic the movement and interactions of atoms and molecules. This technique allows researchers to study complex biological processes at the atomic level, predict protein structures, and design new drugs and materials.

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expanded ensemble simulation

A type of molecular simulation that explores multiple energy states simultaneously.

Expanded ensemble simulations are powerful computational techniques used to study complex systems like proteins. By considering a wider range of possible configurations, researchers can obtain more accurate predictions about protein folding, binding interactions, and other dynamic processes.