A Hydroxyquinoline-Based Unnatural Amino Acid for the Design of Novel Artificial Metalloenzymes

We have examined the potential of the noncanonical amino acid (8-hydroxyquinolin-3-yl)alanine (HQAla) for the design of artificial metalloenzymes. HQAla, a versatile chelator of late transition metals, was introduced into the lactococcal multidrug-resistance regulator (LmrR) by stop codon suppression methodology. LmrR_HQAla was shown to complex efficiently with three different metal ions, Cu-II, Zn(II)and Rh(III)to form unique artificial metalloenzymes. The catalytic potential of the Cu-II-bound LmrR_HQAla enzyme was shown through its ability to catalyse asymmetric Friedel-Craft alkylation and water addition, whereas the Zn-II-coupled enzyme was shown to mimic natural Zn hydrolase activity

PockeMO - the structure of a robust polycyclic ketone monooxygenase as a scaffold for engineering biocatalysts active on bulky substrates

The Baeyer-Villiger oxidation yields esters or lactones from ketones, and this valuable reaction for the introduction of oxygen functionalities is well established in both classic chemistry as well as biocatalysis. It can be particularly beneficial to use flavin-containing enzymes called Baeyer-Villiger monooxygenases (BVMOs), when regio- and stereoselectivity is desired. Achieving this is all the more difficult for bulky, functionalized substrates and while considerable progress has been accomplished by protein engineering, most of the well-studied BVMOs are still limited to relatively small molecules. Another shortcoming of these enzymes is their notorious susceptibility towards heat and solvents. Please click Additional Files below to see the full abstract

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

Unexpected Catalytic Activity of the Regulatory Protein QacR

Natural proteins often present binding or functional promiscuity. In biocatalysis, this promiscuity has been exploited for accessing new-to-nature reactions. Here, we report an unexpected catalytic reactivity for the regulatory protein QacR from the TetR family of multidrug resistance regulators. QacR is able to catalyze the enatioselective tandem Friedel-Crafts / enantioselective protonation reaction of indoles with alpha substituted conjugated enones with up to 40% yield and 83% ee. Mutagenesis and computational studies support the hypothesis that an acidic residue in the binding pocket of the protein is responsible for protonating the enolate intermediate

Polycyclic Ketone Monooxygenase from the Thermophilic Fungus Thermothelomyces thermophila:A Structurally Distinct Biocatalyst for Bulky Substrates

Regio- and stereoselective Baeyer-Villiger oxidations are difficult to achieve by classical chemical means, particularly when large, functionalized molecules are to be converted. Biocatalysis using flavin-containing Baeyer-Villiger monooxygenases (BVMOs) is a well-established tool to address these challenges, but known BVMOs have shortcomings in either stability or substrate selectivity. We characterized a novel BVMO from the thermophilic fungus Thermothelomyces thermophila, determined its three-dimensional structure, and demonstrated its use as a promising biocatalyst. This fungal enzyme displays excellent enantioselectivity, acts on various ketones, and is particularly active on polycyclic molecules. Most notably we observed that the enzyme can perform oxidations on both the A and D ring when converting steroids. These functional properties can be linked to unique structural features, which identify enzymes acting on bulky substrates as a distinct subgroup of the BVMO class

Diminishing benefits of urban living for children and adolescents’ growth and development

Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions