1. Synthesis and structure activity relationships of glycine amide derivatives as novel Vascular Adhesion Protein-1 inhibitors
Susumu Yamaki, et al. Bioorg Med Chem. 2017 Jan 1;25(1):187-201. doi: 10.1016/j.bmc.2016.10.025. Epub 2016 Oct 21.
Vascular Adhesion Protein-1 (VAP-1) is a promising therapeutic target for the treatment of several inflammatory-related diseases including diabetic microvascular complication. We identified glycine amide derivative 3 as a novel structure with moderate VAP-1 inhibitory activity. Structure-activity relationship studies of glycine amide derivatives revealed that the tertiary amide moiety is important for stability in rat blood and that the position of substituents on the left phenyl ring plays an important role in VAP-1 inhibitory activity. We also found that low TPSA values and weak basicity are both important for high PAMPA values for glycine amide derivatives. These findings led to the identification of a series of orally active compounds with enhanced VAP-1 inhibitory activity. Of these compounds, 4g exhibited the most potent ex vivo efficacy, with plasma VAP-1 inhibitory activity of 60% after oral administration at 1mg/kg.
2. Glycine amide shielding on the aromatic surfaces of lysozyme: implication for suppression of protein aggregation
Len Ito, Kentaro Shiraki, Masatomo Makino, Kazuya Hasegawa, Takashi Kumasaka FEBS Lett. 2011 Feb 4;585(3):555-60. doi: 10.1016/j.febslet.2011.01.008. Epub 2011 Jan 14.
Glycine amide (GlyAd), a typically amidated amino acid, is a versatile additive that suppresses protein aggregation during refolding, heat treatment, and crystallization. In spite of its effectiveness, the exact mechanism by which GlyAd suppresses protein aggregation remains to be elucidated. Here, we show the crystal structure of the GlyAd-lysozyme complex by high resolution X-ray crystallographic analysis at a 1.05Å resolution. GlyAd bound to the lysozyme surface near aromatic residues and decreased the amount of bound waters and increased the mobility of protein. Arg and GlyAd molecules are different in binding sites and patterns from glycerol and related compounds, indicating that decreasing hydrophobic patches might be involved in suppression of protein aggregation.
3. Glycine-amide is an active metabolite of the antiretroviral tripeptide glycyl-prolyl-glycine-amide
Elin Andersson, Peter Horal, Alenka Jejcic, Stefan Höglund, Jan Balzarini, Anders Vahlne, Bo Svennerholm Antimicrob Agents Chemother. 2005 Jan;49(1):40-4. doi: 10.1128/AAC.49.1.40-44.2005.
The chemically modified tripeptide glycyl-prolyl-glycine-amide (GPG-NH(2)) inhibits replication of human immunodeficiency virus (HIV) type 1 (HIV-1) in vitro, probably by interfering with capsid formation. The aim of the present study was to determine whether the metabolites glycyl-proline (GP-OH), glycine (G-OH), prolyl-glycine-amide (PG-NH(2)), proline (P-OH), and glycine-amide (G-NH(2)) from proteolytic cleavage may inhibit the replication of HIV-1 in vitro. PG-NH(2) has previously been shown to have a modest effect on HIV-1 replication. In the present study we show that G-NH(2) exhibits a pronounced inhibitory effect on HIV-1. This effect was not due to a decrease in cell proliferation or viability and could not be shown for herpes simplex virus type 1. The G-NH(2) concentration that inhibited virus replication by 50% (IC(50)) was equimolar to that of GPG-NH(2) and ranged from 3 to 41 microM. Transmission electron microscopy revealed that the effect of G-NH(2) on HIV-1 morphology was equivalent to that of GPG-NH(2) and showed disarranged capsid structures, indicating interference with capsid formation. Serial passage of HIV-infected cells with G-NH(2) for more than 20 subcultivations did not decrease the susceptibility to the compound. The results from this study suggest that GPG-NH(2) might act as a prodrug and that G-NH(2) is an active antiretroviral metabolite.
