Deciphering the Unconventional Reduction of C=N Bonds by Old Yellow Enzymes Using QM/MM.

The reduction of C=X (X = N, O) bonds is a cornerstone in both synthetic organic chemistry and biocatalysis. Conventional reduction mechanisms usually involve a hydride ion targeting the less electronegative carbon atom. In a departure from this paradigm, our investigation into Old Yellow Enzymes (OYEs) reveals a mechanism involving transfer of hydride to the formally more electronegative nitrogen atom within a C=N bond.

A Cold-Active Flavin-Dependent Monooxygenase from Unlocks Applications of Baeyer-Villiger Monooxygenases at Low Temperature.

Cold-active enzymes maintain a large part of their optimal activity at low temperatures. Therefore, they can be used to avoid side reactions and preserve heat-sensitive compounds. Baeyer-Villiger monooxygenases (BVMO) utilize molecular oxygen as a co-substrate to catalyze reactions widely employed for steroid, agrochemical, antibiotic, and pheromone production.

Mechanistic Insights into the Ene-Reductase-Catalyzed Promiscuous Reduction of Oximes to Amines.

The biocatalytic reduction of the oxime moiety to the corresponding amine group has only recently been found to be a promiscuous activity of ene-reductases transforming α-oximo β-keto esters. However, the reaction pathway of this two-step reduction remained elusive. By studying the crystal structures of enzyme oxime complexes, analyzing molecular dynamics simulations, and investigating biocatalytic cascades and possible intermediates, we obtained evidence that the reaction proceeds an imine intermediate and not the hydroxylamine intermediate.

Role of glucose variability on linear growth in children with type 1 diabetes.

Objective: Linear growth is impaired in children with type 1 diabetes (T1D) and poor metabolic control. A good metabolic control is a key therapeutic goal to prevent vascular complications and also to ensure appropriate anthropometric development during childhood. In this study, we aimed to identify and characterize the effects of glycemic variability on linear growth in children with T1D.

Insulin resistance relates to DKA severity and affects insulin requirement in children with type 1 diabetes at onset.

Background: Fluid and insulin treatments are the cornerstones of DKA management and indications on dosages are available. However, according to possible confounding factors, relevant data are still required to explain the different insulin dosages adopted at diabetes onset, particularly based upon insulin sensitivity.

Objective: We aimed to explore whether DKA severity is related to different insulin sensitivity states, thus resulting in different insulin requirement at diabetes onset.