We conduct a formal analysis of two biological network circuits, that come about from the cyclic interconnection of motifs that commonly recur in biology. Specifically, we first analyze a generalized version of the gene regulatory network known as the ”repressilator”, which is the interconnection of an arbitrary number of transcriptional regulators connected in feedback. We further analyze an e...

in this study, the effects of dietary egg lecithin on digestive enzymes and body biochemical composition of juveniles mesopotamichthys sharpeyi was evaluated. four experimental diets including control diet (with 0% egg lecithin) and three diets containing 2%, 4% and 6% egg lecithin were used. at the end of the experiment, digestive enzymes activity (lipase, amylase and alkaline phosphatase) and...

the main purpose of this project is investigation of the organophosphorus hydrolase (oph) enzyme activity in water in oil (w/o) and oil in water (o/w) creams and investigation of the oph enzyme stability in formulated creams. oph enzyme was extracted and purified from strain flavobacterium. the w/o and o/w creams were prepared using different formulations. in order to achieve an emulsion with m...

conclusions based on this similarity and our bioinformatics evaluations, this mentioned alpha-amylase gene can be expressed in s. cerevisiae as extracellular enzyme. results the presence of alpha-amylase gene in recombinant bacteria was certificated by colony-pcr method. after extraction of recombinant vector from e. coli, the competent s. cerevisiae cells were transformed using polyethylene gl...

Proteome misfolding and/or aggregation, caused by a thermal perturbation or a related stress, transiently challenges the cellular protein homeostasis (proteostasis) network capacity of cells by consuming chaperone/chaperonin pathway and degradation pathway capacity. Developing protein client-based probes to quantify the cellular proteostasis network capacity in real time is highly desirable. He...

We report the cocrystal structures of a computationally designed and experimentally optimized retro-aldol enzyme with covalently bound substrate analogs. The structure with a covalently bound mechanism-based inhibitor is similar to, but not identical with, the design model, with an RMSD of 1.4 Å over active-site residues and equivalent substrate atoms. As in the design model, the binding pocket...

We study the enzymatic degradation of an elastic fiber under tension using an anisotropic random-walk model coupled with binding-unbinding reactions that weaken the fiber. The fiber is represented by a chain of elastic springs in series along which enzyme molecules can diffuse. Numerical simulations show that the fiber stiffness decreases exponentially with two distinct regimes. The time consta...

The dynamic behavior of metabolic networks is governed by numerous regulatory mechanisms, such as reversible phosphorylation, binding of allosteric effectors or temporal gene expression, by which the activity of the participating enzymes can be adjusted to the functional requirements of the cell. For most of the cellular enzymes, such regulatory mechanisms are at best qualitatively known, where...

In this report, we use synthetic, activity-variant alleles in Drosophila melanogaster to quantify interactions across the enzyme network that reduces nicotinamide adenine dinucleotide phosphate (NADP) to NADPH. We examine the effects of large-scale variation in isocitrate dehydrogenase (IDH) or glucose-6-phosphate dehydrogenase (G6PD) activity in a single genetic background and of smaller-scale...