Computer modeling used to study protein involved with cancer, aging and chronic disease

Apr 13, 2011 By Jianhan Chen and Greg Tammen

(PhysOrg.com) -- A new biophysical and biochemical study may lead to better understanding of how structural flexibility controls the interaction of a protein that is closely involved with cancer, aging and other chronic diseases -- thereby facilitating future development of better therapeutic strategies, according to a Kansas State University biochemist.

Jianhan Chen, an assistant professor of biochemistry, was one of the researchers on a collaborative project that took a combined computational and experimental approach to understand how protein p21 functions as a versatile regulator of cell division. Their latest findings, "Intrinsic disorder mediates the diverse regulatory functions of the Cdk inhibitor p21," were published in a recent edition of .

The study used computer simulation to rationalize results from biochemical and biophysical experiments, and provided further insights that would guide future investigations, Chen said. In this case, the focus is human protein p21 and its ability to function as an inhibitor of normal cell growth.

The protein has been shown to be an intrinsically disordered protein. This means it lacks a well-defined three-dimensional structure, characteristics that, until roughly a decade ago, were thought to be necessary for the protein to function.

"For a long time it was believed that proteins must fold to function and it was hard to imagine how an unfolded protein could play a role in crucial cellular areas," Chen said. "What researchers before me found was that by lacking a stable structure, this actually turned out to be really, really important to how these proteins function."

Along with being an intrinsically disordered protein, p21 is a versatile cyclin-dependent kinase, or Cdk, inhibitor -- meaning it adapts to and inhibits a range of Cdk-cyclin complexes that regulate eukaryote cell division. It also has been connected to cancer and aging. For example, Chen said p21 is a principal trans-activation target of the protein and contributes to p53-dependent tumor suppression.

"This is extremely challenging to study. It's highly dynamic and it's heterogeneous," Chen said. Because of this, mechanistic studies of intrinsically disordered proteins like p21 have been limited. Experiment alone is not sufficient and computer modeling is necessary to provide important missing details, he said. A tight integration of both could lead to a precise understanding of how structural flexibility influences function of p21 and other intrinsically disordered proteins.

"For me this is one of the most interesting IDPs," Chen said. "I'm a theorist and I want to use this system to understand the principles of how this type of proteins can perform their functions. Even though they are disordered, they are not random; there is no chaos. They still have some type of residual structures and certain features which allow function to be controlled in a precise way, and I want to understand the underlying mechanism of how this occurs."

Chen is continuing work with p21 and other small proteins that regulate cell cycles.

Explore further: Chemical biologists find new halogenation enzyme

Related Stories

Common 'chaperone' protein found to work in surprising way

Apr 03, 2011

In the constantly morphing field of protein structure, scientists at The Scripps Research Institute offer yet another surprise: a common "chaperone" protein in cells thought to help other proteins fold has been shown instead ...

Potential new therapeutic molecular target to fight cancer

Nov 01, 2007

Researchers at the Virginia Commonwealth University Massey Cancer Center have identified the enzyme sphingosine kinase 2 as a possible new therapeutic target to improve the efficacy of chemotherapy for colon and breast cancer.

'Linc-ing' a noncoding RNA to a central cellular pathway

Jul 29, 2010

The recent discovery of more than a thousand genes known as large intergenic non-coding RNAs (or "lincRNAs") opened up a new approach to understanding the function and organization of the genome. That surprising breakthrough ...

Recommended for you

Chemical biologists find new halogenation enzyme

14 hours ago

Molecules containing carbon-halogen bonds are produced naturally across all kingdoms of life and constitute a large family of natural products with a broad range of biological activities. The presence of halogen substituents ...

Protein secrets of Ebola virus

20 hours ago

The current Ebola virus outbreak in West Africa, which has claimed more than 2000 lives, has highlighted the need for a deeper understanding of the molecular biology of the virus that could be critical in ...

Protein courtship revealed through chemist's lens

20 hours ago

Staying clear of diseases requires that the proteins in our cells cooperate with one another. But, it has been a well-guarded secret how tens of thousands of different proteins find the correct dancing partners ...

Decoding 'sweet codes' that determine protein fates

22 hours ago

We often experience difficulties in identifying the accurate shape of dynamic and fluctuating objects. This is especially the case in the nanoscale world of biomolecules. The research group lead by Professor Koichi Kato of ...

Conjecture on the lateral growth of Type I collagen fibrils

Sep 12, 2014

Whatever the origin and condition of extraction of type I collagen fibrils, in vitro as well as in vivo, the radii of their circular circular cross sections stay distributed in a range going from 50 to 100 nm for the most ...

User comments : 0