Polypeptides from animal venoms have found important uses as drugs, pharmacological tools, and within biotechnological and agricultural applications. We here report a novel family of cystine knot peptides from nemertean worms, with potent activity on voltage-gated sodium channels. These toxins, named the α-nemertides, were discovered in the epidermal mucus of Lineus longissimus, the ‘bootlace worm’ known as the longest animal on earth. The most abundant peptide, the 31-residue long α-1, was isolated, synthesized, and its 3D NMR structure determined. Transcriptome analysis including 17 species revealed eight α-nemertides, mainly distributed in the genus Lineus. α-1 caused paralysis and death in green crabs (Carcinus maenas) at 1 µg/kg (~300 pmol/kg). It showed profound effect on invertebrate voltage-gated sodium channels (e.g. Blattella germanica Nav1) at low nanomolar concentrations. Strong selectivity for insect over human sodium channels indicates that α-nemertides can be promising candidates for development of bioinsecticidal agents.
The number of pastoralists maintaining production systems with small numbers of traditional breeds of cattle decreased dramatically with the modernisation and industrialisation of agriculture in Europe during the twentieth century. While these pastoral systems were not compatible with agricultural industrialisation policies, they provide a far better match to current European Union (EU) policy with its emphasis on high nature values and various cultural heritage protection measures. Today, these farms can obtain EU funding for preserving natural and/or cultural heritage values rather than producing agricultural goods. Although such EU subsidies make a welcome contribution to the livelihood of traditional farmers, the critical definitions that have to be made regarding what is considered traditional or non-traditional can be problematic. This paper provides an example from Swedish fäbodbruk, a smallholder system of forest pasturing with traditional breeds of cattle, goats and sheep in northern Sweden. As policymaking and agricultural subsidies during the twentieth century reflected the contemporary political agenda of that time, farmers have been subjected to many changes in priority in political decision making. The contemporary push for traditional farming and heritage has made policymaking potentially even more difficult, e.g. as regards the question of what should be considered traditional and what makes up natural and cultural heritage. This paper examines how farmers are affected by valuations and assessments made by the relevant authorities on whether they are producing natural and/or cultural heritage.
Access to land is a key challenge for prospective farmers in Europe. Retiring family farmers who lack a successor resort to leasing or selling their land, but the decision has implications for the community and the rural landscape for generations to come. It is thus crucial to know more about values and decisions linked to keeping, leasing or selling land, and the opportunities these provide for young farmers seeking to establish a business. It is also important to consider the choice of lessee/buyer and the relationship between the former farmer and lessee/buyer. This study is based on interviews with retired farmers, young farmers and farm advisors in Sweden. The results revealed that the lessee/buyer tends to be carefully chosen by the outgoing farmer and that nonmonetary values and motivations, such as social interaction and concern for the environment, the rural community and the agricultural landscape are important. In some cases, the relationship between landowner/former farmer and lessee/buyer resembled family ties. The decision to lease/sell sometimes appeared to be a relief for the retiring farmer. For some lessees/buyers a close relationship with the former farmer provided valuable mentorship, while others valued the greater degree of freedom in leasing/buying compared with inheritance.
This study provides a new method for quantifying the cyclotide kalata B1 in both plasma and brain homogenate. Cyclotides are ultra‐stable peptides with three disulfide bonds that are interesting from a drug development perspective as they can be used as scaffolds. In this study we describe a new validated LC‐MS/MS method with high sensitivity and specificity for kalata B1. The limit of quantification was 2 ng/mL in plasma and 5 ng/gmL in brain homogenate. The method was linear in the range 2–10,000 ng/mL for plasma and 5–2000 ng/g for brain. Liquid Chromatographic separation was performed on a HyPurity C18 column, 50 × 4.6 mm, 3 µm particle size. The method had inter‐ and intra‐day precision and accuracy levels <15% and 12% respectively. Applying the method to in vivo plasma samples and brain homogenate samples from equilibrium dialysis yielded satisfying results and was able to describe the plasma pharmacokinetics and brain tissue binding of kalata B1. The described method is quick, reproducible and well suited to quantifying kalata B1 in biological matrices.
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