Calcium- and calmodulin-independent modulation of calmodulin-sensitive hypothalamic cyclic nucleotide phosphodiesterase activity by the (11-19) fragment of thymosin beta 4.
Galoyan. A A AA; Abrahamian. G E GE; Chailyan. S G SG; Hashim. G A GA; Lajtha. A A
Key Findings
- The (11‑19) fragment of thymosin‑beta‑4 stimulates phosphodiesterase activity without needing calcium or calmodulin.
- Half‑maximal activation occurs at ~10 nM peptide and is enhanced by phospholipids such as phosphatidylserine.
- Stimulation increases the Vmax of cAMP degradation without significantly altering the Km.
Practical Outcomes
- For now, this is a basic science finding with no direct dosing or protocol guidance. It suggests that using this fragment could lower cellular cAMP levels, which might affect metabolism or signaling, but more research is needed before biohackers can apply it safely.
Summary
A short piece of the protein thymosin‑beta‑4 (amino acids 11‑19) can turn on an enzyme that breaks down cAMP, even without calcium or calmodulin. It works at very low concentrations (around 10 nM) and works even better when certain fats like phosphatidylserine are present. The enzyme works faster (higher Vmax) but its affinity for cAMP doesn’t change much.
Abstract
A fragment (11-19) of thymosin beta 4 was found to stimulate phosphodiesterase activity even in the absence of calcium and calmodulin. Half-maximal enzyme activation occurred with 10 nM peptide, and was further increased by phospholipids such as phosphatidylserine. The mechanism of stimulation is an increase in the Vmax of cAMP degradation without a substantial change in the Km for the substrate. In the presence of calcium ions and calmodulin the peptide was also stimulatory.
Study Information
pubmed
1994
10.1007/bf00967323