Mas7 (Mastoparan 7), a structural analogue of mastoparan, is an activator of heterotrimeric Gi proteins and its downstream effectors. In Vitro: Mas7 (Mastoparan 7) produces several biological effects in different cell types. The effect of Mas7 on endogenous mono-ADP-ribosyltransferase activity is in the micromolar range with a maximal activation of 205% over the basal. In pertussis treated plasma membranes, it is found that the effect of Mas7 on endogenous mono-ADP-ribosyltransferase is partially blocked, which suggests the involvement of G-proteins, such as Gi or G0^[1].
Mas7 is a basic tetradecapeptide isolated from isp venom, which activates guanine nucleotide-binding regulatory proteins (G-proteins) and stimulates apoptosis. In smooth muscle cells, Mas7 leads to an increase in the perfusion pressure. Vascular contraction is induced by Mas7. The vasoconstriction triggered by mas-7 exhibited a slower increase compared to that simulated by phenylephrine or vasopressin^[2].
Exposure of hippocampal neurons to a low dose of Mas-7 increases dendritic spine density and spine head width in a time-dependent manner. Additionally, Mas-7 enhances postsynaptic density protein-95 (PSD-95) clustering in neurites and activates Gαo signaling, increasing the intracellular Ca²⁺ concentration^[3].