N-Methyl-D-lysine

Invasive fungal infections (IFIs) represent a growing public concern for clinicians to manage in many medical settings, with substantial associated morbidities and mortalities. Among many current therapeutic options for the treatment of IFIs, amphotericin B (AmB) is the most frequently used drug. AmB is considered as a first-line drug in the clinic that has strong antifungal activity and less resistance. In this review, we summarized the most promising research efforts on nanocarriers for AmB delivery and highlighted their efficacy and safety for treating IFIs. We have also discussed the mechanism of actions of AmB, rationale for treating IFIs, and recent advances in formulating AmB for clinical use. Finally, this review discusses some practical considerations and provides recommendations for future studies in applying AmB for combating IFIs.

Acylation of peptides is a well-known but unwanted phenomenon in polyester matrices such as poly(d,l-lactic-co-glycolic acid) (PLGA) microspheres used as controlled release formulations. Acylation normally occurs on lysine residues and the N-terminus of the peptide. The purpose of the present work was to assess other possible acylation sites on peptides. Goserelin was used as a model peptide that lacks lysine and a free N-terminus, but contains other nucleophilic residues, i.e. serine, tyrosine and arginine, which potentially can be acylated. Goserelin loaded PLGA microspheres were prepared by a double emulsion solvent evaporation technique. Liquid chromatography ion-trap mass spectrometry (LC-ITMS) was used for determining and monitoring acylation of released goserelin. It is demonstrated that arginine is subjected to acylation with glycolic acid and lactic acid units of PLGA, which was followed by loss of NH3 from the guanidine group to obtain 2-oxazolin-4-one and 5-methyl-2-oxazolin-4-one residues with masses that are 41 and 55Da higher, respectively, than the native goserelin. There was no evidence for acylation of serine and tyrosine in goserelin. Our results demonstrate that beside lysine also acylation of arginine can occur in peptides and proteins that are loaded and released from PLGA matrixes.

To separate causal effects of histone acetylation on chromatin accessibility and transcriptional output, we used integrated epigenomic and transcriptomic analyses following acute inhibition of major cellular lysine acetyltransferases P300 and CBP in hematological malignancies. We found that catalytic P300/CBP inhibition dynamically perturbs steady-state acetylation kinetics and suppresses oncogenic transcriptional networks in the absence of changes to chromatin accessibility. CRISPR-Cas9 screening identified NCOR1 and HDAC3 transcriptional co-repressors as the principal antagonists of P300/CBP by counteracting acetylation turnover kinetics. Finally, deacetylation of H3K27 provides nucleation sites for reciprocal methylation switching, a feature that can be exploited therapeutically by concomitant KDM6A and P300/CBP inhibition. Overall, this study indicates that the steady-state histone acetylation-methylation equilibrium functions as a molecular rheostat governing cellular transcription that is amenable to therapeutic exploitation as an anti-cancer regimen.