Research Peptide · For laboratory research use only
Also known as NA Semax, Ac-Semax
N-Acetyl Semax (NA Semax, Ac-Semax) is the N-terminally acetylated form of Semax, a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) that joins the adrenocorticotropic hormone sequence 4-7 to a C-terminal Pro-Gly-Pro tripeptide1. Acetylation of the free N-terminal amino group changes the chemical and biological properties of the parent peptide1, and the stability of acetylated Semax to proteolysis in biological media has been examined2.
Published work on the acetylated form itself is limited to a small number of in vitro and physicochemical studies1,2. Most of the literature concerns the parent compound Semax, studied in rat models of neurotrophin expression and focal cerebral ischaemia3,4,5. Findings for Semax should not be assumed to apply to the acetylated derivative.
As described in the research literature
As described in the research literature, N-terminal acetylation altered how the peptide coordinates copper(II). At physiological pH, Ac-Semax formed a complex with a distorted CuN3O chromophore, whereas Semax formed a CuN4 complex, and the two differed in redox potential and in reactivity towards ascorbic acid. In SH-SY5Y neuroblastoma cells, acetylation removed the protection against copper(II)-induced toxicity seen with the parent peptide, while zinc(II) complex formation and zinc influx were comparable for both forms1.
For the parent compound, studies in rats reported increased BDNF protein, increased trkB tyrosine phosphorylation and raised exon III BDNF and trkB mRNA in the hippocampus3, and time-dependent, region-specific changes in NGF and BDNF gene expression across the hippocampus, frontal cortex and retina4. A genome-wide transcriptional study in a rat permanent middle cerebral artery occlusion model reported that Semax predominantly altered the expression of immune and vascular system genes5.
What published studies have examined
Coordination studies compared the copper(II) and zinc(II) complex species formed by Semax and Ac-Semax, including their redox behaviour. Copper toxicity assays and confocal imaging of zinc influx were carried out in neuroblastoma cells1.
Sources [1]
The stability of acetylated Semax to proteolysis has been examined in various biological media, the property that N-terminal acetylation is generally intended to address2.
Sources [2]
Rat studies of Semax measured hippocampal BDNF protein, trkB phosphorylation and BDNF and trkB mRNA3, and followed NGF and BDNF gene expression over time in the hippocampus, frontal cortex and retina by real-time PCR4.
Genome-wide transcriptional analysis of ischaemic rat cortex examined gene expression 3 and 24 hours after permanent middle cerebral artery occlusion, comparing Semax-treated animals with an ischaemia group5.
Sources [5]
Influence of the N-terminus acetylation of Semax, a synthetic analog of ACTH(4-10), on copper(II) and zinc(II) coordination and biological properties.
Magrì A, Tabbì G, Giuffrida A, et al. Journal of Inorganic Biochemistry, 2016.
Stability of Semax acetyl to proteolysis in various biological media.
Shevchenko KV, Nagaev IY, Andreeva LA, et al. Doklady Biological Sciences, 2013.
Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus.
Dolotov OV, Karpenko EA, Inozemtseva LS, et al. Brain Research, 2006.
Comparison of the temporary dynamics of NGF and BDNF gene expression in rat hippocampus, frontal cortex, and retina under Semax action.
Shadrina M, Kolomin T, Agapova T, et al. Journal of Molecular Neuroscience, 2010.
The peptide semax affects the expression of genes related to the immune and vascular systems in rat brain focal ischemia: genome-wide transcriptional analysis.
Medvedeva EV, Dmitrieva VG, Povarova OV, et al. BMC Genomics, 2014.
This page is provided for research and educational reference only. It does not constitute medical advice, dosing guidance, or a recommendation for use. All compounds are strictly for laboratory and in-vitro research purposes.