Biochemical controls: enzymes control insulin level (Introduction)

by David Turell , Wednesday, December 06, 2023, 14:59 (144 days ago) @ David Turell

Latest study:

https://www.cell.com/cell/fulltext/S0092-8674(23)01226-6?dgcid=raven_jbs_aip_email

"Summary
Acyl-coenzyme A (acyl-CoA) species are cofactors for numerous enzymes that acylate thousands of proteins. Here, we describe an enzyme that uses S-nitroso-CoA (SNO-CoA) as its cofactor to S-nitrosylate multiple proteins (SNO-CoA-assisted nitrosylase, SCAN). Separate domains in SCAN mediate SNO-CoA and substrate binding, allowing SCAN to selectively catalyze SNO transfer from SNO-CoA to SCAN to multiple protein targets, including the insulin receptor (INSR) and insulin receptor substrate 1 (IRS1). Insulin-stimulated S-nitrosylation of INSR/IRS1 by SCAN reduces insulin signaling physiologically, whereas increased SCAN activity in obesity causes INSR/IRS1 hypernitrosylation and insulin resistance. SCAN-deficient mice are thus protected from diabetes. In human skeletal muscle and adipose tissue, SCAN expression increases with body mass index and correlates with INSR S-nitrosylation. S-nitrosylation by SCAN/SNO-CoA thus defines a new enzyme class, a unique mode of receptor tyrosine kinase regulation, and a revised paradigm for NO function in physiology and disease."

Comment: insulin levels are controlled by enzymes at upper and lower levels. Blood sugar levels rise when any food is eaten and arrives in the blood stream. Remember enzymes are highly complex, huge molecules that are exactly specific architecturally built for one specific purpose, to drive one specific reaction. Not by chance. Design is required.