The glycine receptor (GlyR) is a member of the cys-loop family, a group of pentameric ligand-gated ion channels. GlyR play a role in fast inhibitory neurotransmission in brainstem and spinal cord. Several different subunits, e.g. α1, α2,α3 and β, can be found building homomeric and heteromeric channels. Each subunit consists of a transmembrane domain, forming the channel pore, a large extracellular domain, that contains the binding site and a variable intracellular domain. We aim to understand how the agonist molecule interacts with the binding site of the receptor in its resting and activated state, ultimately by using kinetic analysis of single channel records. One approach used here is “mutating” the agonist, i.e. instead of glycine, a series of structurally related small amino acids were used to activate human homomeric α1 GlyR expressed in HEK cells. In the first screen by whole-cell patch-clamp, we found that the enantiomers of alanine, D- and L-alanine, as well as the stereoisomer β-alanine, are interesting candidates for further characterisation. All three molecules appear to be full agonists, but exhibit individual characteristics. β-alanine has an EC50 comparable to glycine (0.16±0.01 vs. 0.10±0.01 mM) whereas L- and D-alanine have a much higher EC50 (7.8±2.2 and 6.5±3.4 mM, respectively). Dose-response curves to glycine and L-alanine have steeper slopes (2.9.±0.1 and 3.8±0.9), whereas β- and D-alanine curves appear shallower (1.2±0.2 and 1.5±1.3).We will present a summary of the kinetic analysis results obtained so far. We use cell-attached patch-clamp to obtain low noise single-channel recordings and analyse them in combination with macroscopic currents evoked by fast agonist application. Our analysis is complemented by computational homology modelling and molecular dynamics calculations that allow us better to interpret our experimental results in regard to the conformational changes of the protein during agonist binding and activation.