The role of propeptide-mediated autoinhibition and intermolecular chaperone in the maturation of cognate catalytic domain in leucine aminopeptidase.

Leucyl aminopeptidase A from Aspergillus oryzae RIB40 (AO-LapA) is an exo-acting peptidase, widely utilised in food debittering applications. AO-LapA is secreted as a zymogen by the host and requires enzymatic cleavage of the autoinhibitory propeptide to reveal its full activity. Scarcity of structural data of zymogen aminopeptidases hampers a better understanding of the details of their molecular action of autoinhibition and how this might be utilised to improve the properties of such enzymes by recombinant methods for more effective bioprocessing.

Sense of Community on Twitter and Instagram: Exploring the Roles of Motives and Parasocial Relationships.

Although research has explored the ways in which people form virtual communities to converse about media figures, television shows, and similar topics, little research has examined the link between virtual communities and the parasocial relationships (PSRs) that are often the focus of these conversations and users' experiences in those virtual communities. We examined sense of community (SOC) on Twitter and Instagram as a function of users' motives for use and users' PSR on the sites. In addition to examining the relative importance of different motives for using Twitter and Instagram, we predicted that PSR would mediate the association between motives for use and SOC.

An Exploratory Investigation of Communication Technologies to Alleviate Communicative Difficulties and Depression in Older Adults.

Objective: To explore associations between older adults' communicative difficulties, depressive symptoms, and e-mail and telephone use with adult children.

Method: We examined these associations using data from 1,634 participants (age M = 71.16, SD = 0.

Mutations affecting the extreme C terminus of Escherichia coli haemolysin A reduce haemolytic activity by altering the folding of the toxin.

Escherichia coli haemolysin A (HlyA), an RTX toxin, is secreted probably as an unfolded intermediate, by the type I (ABC transporter-dependent) pathway, utilizing a C-terminal secretion signal. However, the mechanism of translocation and post-translocation folding is not understood. We identified a mutation (hlyA99) at the extreme C terminus, which is dominant in competition experiments, blocking secretion of the wild-type toxin co-expressed in the same cell.

From insects to human hosts: Identification of major genomic differences between entomopathogenic strains of Photorhabdus and the emerging human pathogen Photorhabdus asymbiotica.

Pathogenic bacteria of the genus Photorhabdus are naturally found in symbiotic association with soil entomopathogenic nematodes, and are of increasing economic interest in view of their potential for the development of novel biopesticides. This bipartite natural system is currently used for the biological control of crop pests in several countries. However, an increasing number of Photorhabdus strains have recently been isolated from human clinical specimens in both the United States and Australia, associated with locally invasive soft tissue infections and disseminated bacteraemia.