Although the pursuit of such goals can be a negatively “”stressful”"

experience, it is not necessarily so. According to the biopsychosocial model of challenge and threat, evaluations of personal resources and situational demands determine to what extent individuals experience a relatively positive (challenge) versus negative (threat) psychological state in this context. Challenge occurs when evaluated resources meet or exceed demands, whereas threat occurs when demands exceed resources. The challenge response thus reflects resilience in the face of potential stress. Because challenge and threat reliably Idasanutlin order result in distinct patterns of physiological changes, assessing cardiovascular responses in particular can provide valuable insight into underlying psychological processes. Research applying this methodology to individual differences (e.g., self-esteem level and stability and cumulative lifetime exposure to adversity) has implications for understanding how early life experience could contribute to resilience

versus vulnerability to potential stress in daily life. (C) 2011 Elsevier Ltd. All rights reserved.”
“Background: Throughout evolution, mutations in particular find more regions of some protein structures have resulted in extra covalent bonds that increase the overall robustness of the fold: disulfide bonds. The two strategically placed cysteines can also have a more direct role in protein function, either by assisting thiol or disulfide exchange, or through allosteric effects. In this work, we verified how

the structural similarities learn more between disulfides can reflect functional and evolutionary relationships between different proteins. We analyzed the conformational patterns of the disulfide bonds in a set of disulfide-rich proteins that included twelve SCOP superfamilies: thioredoxin-like and eleven superfamilies containing small disulfide-rich proteins (SDP).

Results: The twenty conformations considered in the present study were characterized by both structural and energetic parameters. The corresponding frequencies present diverse patterns for the different superfamilies. The least-strained conformations are more abundant for the SDP superfamilies, while the “”catalytic”" +/-RHook is dominant for the thioredoxin-like superfamily. The “”allosteric”" -RHSaple is moderately abundant for BBI, Crisp and Thioredoxin-like superfamilies and less frequent for the remaining superfamilies. Using a hierarchical clustering analysis we found that the twelve superfamilies were grouped in biologically significant clusters.

Conclusions: In this work, we carried out an extensive statistical analysis of the conformational motifs for the disulfide bonds present in a set of disulfide-rich proteins.