Site‐Specific SERS Assay for Survivin Protein Dimer: From Ensemble Experiments to Correlative Single‐Particle Imaging

An assay for Survivin, a small dimeric protein which functions as modulator of apoptosis and cell division and serves as a promising diagnostic biomarker for different types of cancer, is presented. The assay is based on switching on surface‐enhanced Raman scattering (SERS) upon incubation of the Survivin protein dimer with Raman reporter‐labeled gold nanoparticles (AuNP). Site‐specificity is achieved by complexation of nickel‐chelated N‐nitrilo‐triacetic acid (Ni‐NTA) anchors on the particle surface by multiple histidines (His₆‐tag) attached to each C‐terminus of the centrosymmetric protein dimer. Correlative single‐particle analysis using light sheet laser microscopy enables the simultaneous observation of both elastic and inelastic light scattering from the same sample volume. Thereby, the SERS‐inactive AuNP‐protein monomers can be directly discriminated from the SERS‐active AuNP‐protein dimers/oligomers. This information, i.e. the percentage of SERS‐active AuNP in colloidal suspension, is not accessible from conventional SERS experiments due to ensemble averaging. The presented correlative single‐particle approach paves the way for quantitative site‐specific SERS assays in which site‐specific protein recognition by small chemical and in particular supramolecular ligands can be tested.     

Characterization of soybean seed coat peroxidase: resonance Raman evidence for a structure-based classification of plant peroxidases

Electronic absorption and resonance Raman spectra of ferric and ferrous forms of a peroxidase from soybean seed coat (SBP) at neutral and alkaline pH values together with the spectra of the ferric-fluoride complex are reported. At neutral pH a quantum mechanically mixed spin state, resulting from the admixture of intermediate spin, S = 3/2, and high spin, S = 5/2, configurations, has been identified which coexists with five- and six-coordinate high-spin hemes. A complete conversion to a fluoride-ligated six-coordinate high-spin and a hydroxy-ligated six-coordinate low-spin heme are observed at acid pH in the presence of fluoride and at alkaline pH, respectively. The spectral features suggest that both the fluoride and hydroxo ligands are stabilized by hydrogen-bond interactions with the distal Arg residue and through a water molecule with the distal His residue. The ferrous form shows a single nu(Fe-Im) at 246 cm(-1) at neutral pH. The data indicate that SBP shares many characteristics with peroxidases belonging to class III of the "plant peroxidase" superfamily.     

Domain Taxonomy for Construction Concepts: Toward a Formal Ontology for Construction Knowledge

With the advancement of the semantic web, the construction industry is at a stage where intelligent knowledge management systems can be used. Such systems support more effective collaboration, where virtual teams of skilled users, not software, exchange ideas, decisions, and best practice. To achieve that, there is a need to create consistent semantic representation of construction knowledge. Existing representations, in the form of classification systems and product data models, lack effective modeling of concept semantics—a fundamental requirement for human-based exchange of knowledge. Toward this objective, this paper presents a domain taxonomy that was developed as part of the e-COGNOS project. The taxonomy was developed as a first step in the establishment of domain ontology for construction. The taxonomy was developed to be process-centered and to allow for utilization of already existing classification systems (BS6100, Master Format, and UniClass, for example). The taxonomy uses seven major domains to classify construction concepts: Process, Product, Project, Actor, Resource, Technical Topics, and Systems. The taxonomy was developed and validated through extensive interaction with domain experts. The taxonomy was used to develop a prototype ontology for the construction domain including semantic relationships and axioms. The ontology was used to support several applications in semantic knowledge management as part of the e-COGNOS portal, including semantic indexing and retrieval of information and ontology-based collaborative project development.     

Graduate training and employment experiences of community psychologists.

We surveyed the graduate training and employment experiences of 177 current students and 152 recent graduates from 39 psychology programs. Of interest were differences among applied social, community and community-clinical programs. Results suggested that these training programs represented a continuum of research, community, and clinical interests. Applied social and community programs had a stronger community and research emphasis, whereas community-clinical programs had a stronger orientation toward clinical skills. Similarly, the job skills used by recent graduates suggested that persons from applied social programs went into administrative and organizational consulting jobs, graduates of community-clinical programs were employed in areas demanding more human services skills, and community graduates found jobs requiring the use of research skills. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fifteen years of Raman spectroscopy of engineered heme containing peroxidases: what have we learned?

Spectroscopic techniques have been fundamental to the comprehension of peroxidase function under physiological conditions. This Account examines the contribution to our understanding of heme peroxidases provided by electronic and resonance Raman spectroscopies in conjunction with site-directed mutagenesis. The results obtained over 15 years with several heme peroxidases and selected mutants have provided important insights into the influence exerted by the protein in the vicinity of the active site via key amino acids on the functionality and stability of the enzymes. Moreover, resonance Raman spectroscopy has revealed that a common feature of heme peroxidases is the presence of an extensive network of H-bonds coupling the distal and proximal sides, which has a profound influence on the heme ligation, affecting both the fifth and the sixth coordination sites.