Structural Analysis and Substrate Specificity of D-Carbamoylase from .

The synthesis of enantiomeric forms of D-amino acids can be achieved by a two-step "hydantoinase process" based on the sequential catalysis of substrates by specific enzymes, D-carbamoylase and D-hydantoinase. Here, we describe the structural features of D-carbamoylase from , the encoded gene of which was chemically synthesized and cloned into . A significant fraction of the overexpressed recombinant protein forms insoluble inclusion bodies, which are partially converted to a soluble state upon treatment with N-lauroylsarcosine or upon incubation of cells at 28 °C.

Structural and biochemical characterisation of the N-carbamoyl-β-alanine amidohydrolase from Rhizobium radiobacter MDC 8606.

N-carbamoyl-β-alanine amidohydrolase (CβAA) constitutes one of the most important groups of industrially relevant enzymes used in the production of optically pure amino acids and derivatives. In this study, a CβAA-encoding gene from Rhizobium radiobacter strain MDC 8606 was cloned and overexpressed in Escherichia coli. The purified recombinant enzyme (RrCβAA) showed a specific activity of 14 U·mg using N-carbamoyl-β-alanine as a substrate with an optimum activity at 55 °C and pH 8.

Incidence and Risk Factors for Acute Kidney Injury and Its Effect on Mortality in Patients Hospitalized From COVID-19.

Objective: To determine the incidence of and risk factors for the development of acute kidney injury (AKI) and investigate the association between AKI and mortality in patients hospitalized with coronavirus disease 2019 (COVID-19) infection.

Patients And Methods: This retrospective case series includes the first 370 patients consecutively hospitalized with confirmed COVID-19 illness between March 10, 2020, and May 13, 2020, at a 242-bed teaching hospital. To determine independent associations between demographic factors, comorbid conditions, and AKI incidence, multivariable logistic regression models were used to estimate odds ratios adjusted for clinical covariates.

Rational Engineering of the Substrate Specificity of a Thermostable D-Hydantoinase (Dihydropyrimidinase).

D-hydantoinases catalyze an enantioselective opening of 5- and 6-membered cyclic structures and therefore can be used for the production of optically pure precursors for biomedical applications. The thermostable D-hydantoinase from ATCC 31783 is a manganese-dependent enzyme and exhibits low activity towards bulky hydantoin derivatives. Homology modeling with a known 3D structure (PDB code: 1K1D) allowed us to identify the amino acids to be mutated at the substrate binding site and in its immediate vicinity to modulate the substrate specificity.