Kalata B8, a novel antiviral circular protein, exhibits conformational flexibility in the cystine knot motif

The cyclotides are a family of circular proteins with a range of biological activities and potential pharmaceutical and agricultural applications. The biosynthetic mechanism of cyclization is unknown and the discovery of novel sequences may assist in achieving this goal. In the present study, we have isolated a new cyclotide from Oldenlandia affinis, kalata B8, which appears to be a hybrid of the two major subfamilies (Mobius and bracelet) of currently known cyclotides. We have determined the three-dimensional structure of kalata B8 and observed broadening of resonances directly involved in the cystine knot motif, suggesting flexibility in this region despite it being the core structural element of the cyclotides. The cystine knot motif is widespread throughout Nature and inherently stable, making this apparent flexibility a surprising result. Further-more, there appears to be isomerization of the peptide backbone at an Asp-Gly sequence in the region involved in the cyclization process. Interestingly, such isomerization has been previously characterized in related cyclic knottins from Momordica cochinchinensis that have no sequence similarity to kalata B8 apart from the six conserved cysteine residues and may result from a common mechanism of cyclization. Kalata B8 also provides insight into the structure-activity relationships of cyclotides as it displays anti-HIV activity but lacks haemolytic activity. The 'uncoupling' of these two activities has not previously been observed for the cyclotides and may be related to the unusual hydrophilic nature of the peptide.

An investigation into leader behavioural flexibility

No abstract

Pockets of flexibility in workflow specification

Workflow technology is currently being deployed in quite diverse domains. However, the element of change is present in some degree and form in almost all domains. A workflow implementation that does not support the process of change will not benefit the organization in the long run. Change can be manifested in different forms in workflow processes. In this paper, we first present a categorization of workflow change characteristics and divide workflow processes into dynamic, adaptive and flexible processes. We define flexibility as the ability of the workflow process to execute on the basis of a loosely, or partially specified model, where the full specification of the model is made at runtime, and may be unique to each instance. To provide a modeling framework that offers true flexibility, we need to consider the factors, which influence the paths of (unique) instances together with the process definition. We advocate an approach that aims at making the process of change part of the workflow process itself. We introduce the notion of an open instance that consists of a core process and several pockets of flexibility, and present a framework based on this notion, which makes use of special build activities that provide the functionality to integrate the process of defining a change, into the open workflow instance.

Youth, Religion and Participation : Theoretical and Methodological Approaches

This roundtable session focus on religious and social change as well as democracy and political culture, startingfrom the role of youth in these processes. The role of religion in young people’s participation is a key theme inthe cross-disciplinary network “youth and religion” connected to the Impact program. Participation here includesboth citizens’ “vertical” capacities to make their voices heard and influence decision-makers in the political system(e.g. via elections or civic organizations and social movements) and their “horizontal” capacities to communicateand cooperate with other people (within society at large or certain associations/communities). The participants ofthe session will present influential theories and methodologies used to study participation among youth within theresearch disciplines they represent (i.e. sociology of religion; theology; ethnology; political science). This will befollowed by a joint discussion of how these theories and methodologies have approached religious involvement witha particular focus on youth’s participation in politics, civil society as well as social media and the internet. The aim ofthe session is to look for common themes and new issues that can guide contemporary studies of participation in thefield of youth and religion. The session is open to conference participants interested in the issues discussed.