We report the utilization of microfluidic technology to phage selection and demonstrate that accurate control of washing stringency in our microfluidic magnetic separator (MMS) directly impacts the diversity of isolated peptide sequences. Reproducible generation of magnetic and fluidic forces allows controlled washing conditions that enable rapid convergence of selected peptide sequences. These findings may provide a foundation for the development of automated microsystems for rapid in vitro directed evolution of affinity reagents.
The paper analyzed the global growth and development of flipped classroom research productivity in terms of publication output as reflected in SCI/SSCI for the period 2000-2015. Publication types and languages, characteristics of articles outputs, countries, subject categories and journals, and the frequency of keywords were analyzed using bibliometric methods. There are 149 articles in 78 journals listed in 41 SCI/SSCI subject categories. A sharp growth trend of publication output was observed during 2011-2015. USA played a predominant role in flipped classroom research. Education educational research, chemistry and medical were the top 3 categories and “active learning” and “blended learning” recent major topics of flipped classroom research during the past 16 years. The results could help researchers understand the characteristics of research output and search hot spots of flipped education field.
It has been shown that highly conserved residues that form crucial structural elements of the catalytic apparatus may be used to account for the evolutionary history of enzymes. Using saturation mutagenesis, we investigated the role of a conserved residue (Arg 526 ) at the active site of acylaminoacyl peptidase from hyperthermophilic Aeropyrum pernix K1 in substrate discrimination and catalytic mechanism. This enzyme has both peptidase and esterase activities. The esterase activity of the wild-type enzyme with p-nitrophenyl caprylate as substrate is ϳ7 times higher than the peptidase activity with Ac-Leu-p-nitroanilide as substrate. However, with the same substrates, this difference was increased to ϳ150-fold for mutant R526V. A more dramatic effect occurred with mutant R526E, which essentially completely abolished the peptidase activity but decreased the esterase activity only by a factor of 2, leading to a 785-fold difference in the enzyme activities. These results provide rare examples that illustrate how enzymes can be evolved to discriminate their substrates by a single mutation. The possible structural and energetic effects of the mutations on k cat and K m of the enzyme were discussed based on molecular dynamics simulation studies.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.