Enzymatic synthesis of N-acetyllactosamine from lactose enabled by recombinant β1,4-galactosyltransferases

Utilising a fast and sensitive screening method based on imidazolium-tagged probes, we report unprecedented reversible activity of bacterial β1,4-galactosyltransferases to catalyse the transgalactosylation from lactose to N-acetylglucosamine to form N-acetyllactosamine in the presence of UDP. The process is demonstrated by the preparative scale synthesis of pNP-β-LacNAc from lactose using β1,4-galactosyltransferase NmLgtB-B as the only biocatalyst

The Emergence of Shell Valuable Exchange in the New Guinea Highlands

Shell valuable exchange in the New Guinea Highlands has been a key interest in anthropology, providing insight into economics, aesthetics, and social stratification amongst banded communities. This paper describes how shell exchange at ethnographic present reflects deeper historical processes. We trace the origins and subsequent changes in shell use from the terminal Pleistocene to the Late Holocene at the site of Kiowa in Chimbu Province, Papua New Guinea. Zooarchaeological and technological analyses of Kiowa’s shell artifacts indicates riverine mussel was procured locally from the terminal Pleistocene (9,500–10,000 years ago) and featured as a minor component in the diet into the recent precolonial period. In contrast, evidence for marine shell valuables only appears in the Late Holocene in the form of Trochus armbands and Tegillarca granosa and Polymesoda cf. erosa multifunctional tools. This challenges ideas that associate the gradual dispersal of marine shell into the highlands with the spread of agriculture around the Wahgi Valley at the start of the Holocene, and supports punctuated pulses of coastal contact. In doing so, we formulate a testable model for the development of shell exchange into the highlands, with implications for the emergence of stratification and the conduits between the interior and coast

Oxygen tension regulates the miRNA profile and bioactivity of exosomes released from extravillous trophoblast cells - liquid biopsies for monitoring complications of pregnancy

Our understanding of how cells communicate has undergone a paradigm shift since the recent recognition of the role of exosomes in intercellular signaling. In this study, we investigated whether oxygen tension alters the exosome release and miRNA profile from extravillous trophoblast (EVT) cells, modifying their bioactivity on endothelial cells (EC). Furthermore, we have established the exosomal miRNA profile at early gestation in women who develop pre-eclampsia (PE) and spontaneous preterm birth (SPTB). HTR-8/SVneo cells were used as an EVT model. The effect of oxygen tension (i.e. 8% and 1% oxygen) on exosome release was quantified using nanocrystals (Qdot®) coupled to CD63 by fluorescence NTA. A real-time, live-cell imaging system (Incucyte™) was used to establish the effect of exosomes on EC. Plasma samples were obtained at early gestation (<18 weeks) and classified according to pregnancy outcomes. An Illumina TrueSeq Small RNA kit was used to construct a small RNA library from exosomal RNA obtained from EVT and plasma samples. The number of exosomes was significantly higher in EVT cultured under 1% compared to 8% oxygen. In total, 741 miRNA were identified in exosomes from EVT. Bioinformatic analysis revealed that these miRNA were associated with cell migration and cytokine production. Interestingly, exosomes isolated from EVT cultured at 8% oxygen increased EC migration, whilst exosomes cultured at 1% oxygen decreased EC migration. These changes were inversely proportional to TNF-α released from EC. Finally, we have identified a set of unique miRNAs in exosomes from EVT cultured at 1% oxygen and exosomes isolated from the circulation of mothers at early gestation, who later developed PE and SPTB. We suggest that aberrant exosomal signalling by placental cells is a common aetiological factor in pregnancy complications characterised by incomplete SpA remodeling and is therefore a clinically relevant biomarker of pregnancy complications.Grace Truong, Dominic Guanzon, Vyjayanthi Kinhal, Omar Elfeky, Andrew Lai, Sherri Longo, Zarin Nuzhat, Carlos Palma, Katherin Scholz-Romero, Ramkumar Menon, Ben W. Mol, Gregory E. Rice, Carlos Salomo

Recent advances in enzymatic synthesis of β-glucan and cellulose

Bottom-up synthesis of β-glucans such as callose, fungal β-(1,3)(1,6)-glucan and cellulose, can create the defined compounds that are needed to perform fundamental studies on glucan properties and develop applications. With the importance of β-glucans and cellulose in high-profile fields such as nutrition, renewables-based biotechnology and materials science, the enzymatic synthesis of such relevant carbohydrates and their derivatives has attracted much attention. Here we review recent developments in enzymatic synthesis of β-glucans and cellulose, with a focus on progress made over the last five years. We cover the different types of biocatalysts employed, their incorporation in cascades, the exploitation of enzyme promiscuity and their engineering, and reaction conditions affecting the production as well as in situ self-assembly of (non)functionalised glucans. The recent achievements in the application of glycosyl transferases and β-1,4- and β-1,3-glucan phosphorylases demonstrate the high potential and versatility of these biocatalysts in glucan synthesis in both industrial and academic contexts

Technology for nurture in large undergraduate statistics classes

This paper reports on a practitioner study of a first-year undergraduate service course that aligns a web-based, student-lecturer communication system with the mathematical curriculum. The report presents and analyses data from students and from the lecturer and outlines the nature of the technical interface. The paper indicates how communication of the students affective learning needs had a positive influence on the professional development of the lecturer himself. Furthermore, it is claimed that the success of mathematics/statistics teaching that integrates emotional responses from learners is intimately related to the knowledge, skills, beliefs and values of the lecturer