(S)-Ro 32-0432 is a potent, selective inhibitor of protein kinase C (PKC) and G protein-coupled receptor kinase 5 (GRK5), demonstrating ATP-competitive and oral activity. It presents IC50 values of 9.3 nM for PKCα, 28 nM for PKCβI, 30 nM for PKCβII, 36.5 nM for PKCγ, and 108.3 nM for PKCε, showcasing its effectiveness against multiple PKC isoforms. Additionally, (S)-Ro 32-0432 inhibits T-cell activation, indicating its potential application in the research of chronic inflammatory and autoimmune diseases [1] [2].

(S)-Ro 32-0432 effectively suppresses interleukin-2 (IL-2) secretion, IL-2 receptor expression, and proliferation in human peripheral T-cells when activated with phorbol ester alongside phytohemagglutin or anti-CD3. However, it does not affect IL-2 induced proliferation in cells that have already been stimulated to express IL-2 receptors. Furthermore, this compound hinders the proliferation of the influenza peptide antigen HA 307-319-specific human T-cell clone (HA27) when these cells encounter antigen-presenting cells. Specifically, (S)-Ro 32-0432 demonstrates an inhibitory concentration (IC 50) of 0.15 μM [1], indicating its potency in blocking HA27 proliferation.