A Collection of Single-Domain Antibodies that Crowd Ricin Toxin’s Active Site

This work is licensed under a Creative Commons Attribution 4.0 International License.In this report, we used hydrogen exchange-mass spectrometry (HX-MS) to identify the epitopes recognized by 21 single-domain camelid antibodies (VHHs) directed against the ribosome-inactivating subunit (RTA) of ricin toxin, a biothreat agent of concern to military and public health authorities. The VHHs, which derive from 11 different B-cell lineages, were binned together based on competition ELISAs with IB2, a monoclonal antibody that defines a toxin-neutralizing hotspot (“cluster 3”) located in close proximity to RTA’s active site. HX-MS analysis revealed that the 21 VHHs recognized four distinct epitope subclusters (3.1–3.4). Sixteen of the 21 VHHs grouped within subcluster 3.1 and engage RTA α-helices C and G. Three VHHs grouped within subcluster 3.2, encompassing α-helices C and G, plus α-helix B. The single VHH in subcluster 3.3 engaged RTA α-helices B and G, while the epitope of the sole VHH defining subcluster 3.4 encompassed α-helices C and E, and β-strand h. Modeling these epitopes on the surface of RTA predicts that the 20 VHHs within subclusters 3.1–3.3 physically occlude RTA’s active site cleft, while the single antibody in subcluster 3.4 associates on the active site’s upper rim.National Institutes of Allergy and Infectious Diseases, National Institutes of Health (HHSN272201400021C

An ATP and Oxalate Generating Variant Tricarboxylic Acid Cycle Counters Aluminum Toxicity in Pseudomonas fluorescens

Although the tricarboxylic acid (TCA) cycle is essential in almost all aerobic organisms, its precise modulation and integration in global cellular metabolism is not fully understood. Here, we report on an alternative TCA cycle uniquely aimed at generating ATP and oxalate, two metabolites critical for the survival of Pseudomonas fluorescens. The upregulation of isocitrate lyase (ICL) and acylating glyoxylate dehydrogenase (AGODH) led to the enhanced synthesis of oxalate, a dicarboxylic acid involved in the immobilization of aluminum (Al). The increased activity of succinyl-CoA synthetase (SCS) and oxalate CoA-transferase (OCT) in the Al-stressed cells afforded an effective route to ATP synthesis from oxalyl-CoA via substrate level phosphorylation. This modified TCA cycle with diminished efficacy in NADH production and decreased CO2-evolving capacity, orchestrates the synthesis of oxalate, NADPH, and ATP, ingredients pivotal to the survival of P. fluorescens in an Al environment. The channeling of succinyl-CoA towards ATP formation may be an important function of the TCA cycle during anaerobiosis, Fe starvation and O2-limited conditions

New directions for institutional research

Publ. comme no 106, summer 2000 de la revue New directions for institutional researchBibliogr. à la fin des textesIndex: p. 103-10

Understanding Faculty Productivity: Standards and Benchmarks for Colleges and Universities

An invaluable resource for any college and university striving to meet the National Cost Commission\u27s call to make what colleges do and what it costs more \u27transparent\u27 to the public. --Jacqueline E. King, director, federal policy analysis, American Council on EducationDefining and measuring faculty productivity are among the most central issues for quality and accountability in higher education. Known for assembling some of the most authoritative research on faculty productivity--and for analyzing its impact on academic and institutional accountability--Michael F. Middaugh presents this comprehensive volume to help campus professionals build greater accountability for students, parents, foundations, governmental organizations, and other concerned constituents. Middaugh first draws from a research study funded by TIAA-CREF\u27s Cooperative Research Grant Program and the Fund for Postsecondary Education within the U.S. Department of Education. He then provides a new framework for analyzing faculty efficiency and emphasizes how the results of faculty work can become the best indicators of productivity. He also applies the joint study findings to the task of developing benchmarks for faculty productivity. Practitioners from any type of campus will find a rich array of data, valuable recommendations, and relevant examples

Embryo Ecology of the Pacific Surf Smelt, Hypomesus pretiosus (Pisces: Osmeridae)

A study of the ecology of developing embryos of the Pacific surf smelt, Hypomesus pretiosus, was conducted. Embryos were maintained in the laboratory at 7.6, 12.1, and 17.6°C and the time to specific embryonic stages determined. Embryos held at 7.6°C developed to stage 24, 18 days after collection; those held at 12.1°C hatched after 13 days; at 17.6°C hatching occurred 8.5 days after collection. Embryos maintained at 15°C and salinities of 20, 25, and 30%0 averaged 84% survival. There was no significant difference in survival between the groups (ANOVA, P = 0.53). Field observations indicated that embryos are spawned in patches in the upper intertidal zone near the time of high tide. They are attached to gravel substrates by the zona radiata membrane which ruptures and quickly turns inside out at the time embryos are fertilized. After several days of development, stage 18 to 22 embryos detach from the original spawning substrates and are washed seaward and down into the gravel substrate in the intertidal zone. However, there was no significant difference (ANOVA, P >2: 0.09) in the number of eggs found at each of 4 depth strata in the upper, middle, and lower intertidal zones

Planning and assessment in higher education: demonstrating institutional effectiveness

xiii+240hlm.;23c

Evolution and Design of Protein Structure by Folding Nucleus Symmetric Expansion

SummaryModels of symmetric protein evolution typically invoke gene duplication and fusion events, in which repetition of a structural motif generates foldable, stable symmetric protein architecture. Success of such evolutionary processes suggests that the duplicated structural motif must be capable of nucleating protein folding. If correct, symmetric expansion of a folding nucleus sequence derived from an extant symmetric fold may be an elegant and computationally tractable solution to de novo protein design. We report the efficient de novo design of a β-trefoil protein by symmetric expansion of a β-trefoil folding nucleus, previously identified by ɸ-value analysis. The resulting protein, having exact sequence symmetry, exhibits superior folding properties compared to its naturally evolved progenitor—with the potential for redundant folding nuclei. In principle, folding nucleus symmetric expansion can be applied to any given symmetric protein fold (that is, nearly one-third of the known proteome) provided information of the folding nucleus is available