The structure of the protein responsible for the health of the heart and nervous system is deciphered
Last reviewed: 16.10.2021
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Scientists at the University of Michigan (UM) deciphered the structure of the protein, which is an integral part of the process responsible for maintaining the health of the heart and nervous system of man.
This protein is cystathionine-beta-synthase (cystathionine beta-synthase, SBC). For the synthesis of hydrogen sulfide (H2S), a gaseous signal molecule that helps maintain the health of the heart and the nervous system, CBS uses vitamin B6. In animals, H2S causes a state of suspended animation, or hibernation, reducing body temperature and decreasing metabolic rate.
Work on deciphering the structure was conducted under the guidance of Professor Ruma Banerjee, Professor of the Department of Biochemistry of the Medical School of the University of Michigan (UM Medical School), Prof. Dr. Janet Smith, Professor of Life Sciences Institute of the UM of the Doctor of Philosophy, and their colleagues. The results are published in the journal Proceedings of the National Academy of Sciences.
"The structure of the protein CBS, which has eluded scientists for more than ten years, provides a lot of new information about the formation of an enzyme gas, which is especially important for the brain," Banerjee said. "The interpretation of this structure provides a basis for understanding the mutations that cause homocystinuria - a hereditary disease that affects the vision, skeletal, cardiovascular and central nervous system."
For the first time seen, the complete structure of CBS gives an explanation for the homocystinuria caused by defects in this protein at the molecular level.
The enzyme activity is enhanced by SAMe (S-adenosylmethionine), a food additive used as an antidepressant and an anti-inflammatory agent. Linking to CBS, SAMe increases the production of hydrogen sulphide.
"Understanding the molecular level of the architecture of the CBS domain, with which SAMe interacts, opens the door for rational drug development to fine tune hydrogen sulfide production for pharmacological purposes," says Dr. Markos Koutmos, Ph.D., a member of the Smith research group.
Scientists seized the enzyme CBS at two points of its complex chemical reaction, "catching" two highly reactive chemical intermediates in the active center of the enzyme. Their structures reveal the details of how vitamin B6 helps CBS conduct complex reactions leading to the formation of hydrogen sulphide.
Important chemical details seen by researchers in CBS may be useful for deciphering the structure of other human enzymes that depend on vitamin B6, which are more than 50.