Two new species of stream-dwelling crayfish, Cambarus lapidosus, the Stony Fork Crayfish, and Cambarus burchfielae, the Falls Crayfish, are described from the Yadkin River basin in western North Carolina, USA, using an integrative taxonomic approach consisting of morphological, genetic, and biogeographic data. Both species were previously considered to be members of the widely distributed Cambarus species C complex, which occurs throughout mid-Atlantic Slope river basins; however, they are in fact morphologically and genetically more similar to the Cambarus robustus species complex from interior basins in the south-central Appalachians, indicating Atlantic basin stream capture of an Interior basin faunal group has occurred in this region. Both new species described herein can be differentiated from these two complexes, and each other, by several morphological characteristics.
View Article and Find Full Text PDFProtein structure, function, and evolution depend on local and collective epistatic interactions between amino acids. A powerful approach to defining these interactions is to construct models of couplings between amino acids that reproduce the empirical statistics (frequencies and correlations) observed in sequences comprising a protein family. The top couplings are then interpreted.
View Article and Find Full Text PDFThis article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).
View Article and Find Full Text PDFThe ribosome translates the genetic code into proteins in all domains of life. Its size and complexity demand long-range interactions that regulate ribosome function. These interactions are largely unknown.
View Article and Find Full Text PDFThe rational design of enzymes is an important goal for both fundamental and practical reasons. Here, we describe a process to learn the constraints for specifying proteins purely from evolutionary sequence data, design and build libraries of synthetic genes, and test them for activity in vivo using a quantitative complementation assay. For chorismate mutase, a key enzyme in the biosynthesis of aromatic amino acids, we demonstrate the design of natural-like catalytic function with substantial sequence diversity.
View Article and Find Full Text PDFA new species of stream-dwelling crayfish, Cambarus franklini, the South Mountains crayfish, is described from the upper South Fork Catawba River basin in western North Carolina, USA using morphological and genetic data. Cambarus franklini was previously considered a member of the widespread and morphologically variable Cambarus species C complex and is morphologically most similar to an undiagnosed member of the group native to the upper Catawba River basin in NC. Cambarus franklini can be differentiated from this species group by several morphological characteristics including: lacking a well-defined double row of tubercles along the mesial margin of the palm, possessing a more weakly convergent and longer acumen, and conspicuous blue-green and red coloration, particularly throughout the telson and along the distal margins of the rami.
View Article and Find Full Text PDFThe design and synthesis of novel genes and deoxyribonucleic acid (DNA) sequences is a central technique in synthetic biology. Current methods of high throughput gene synthesis use pooled oligonucleotides obtained from custom-designed DNA microarray chips, and rely on orthogonal (non-interacting) polymerase chain reaction primers to specifically de-multiplex, by amplification, the precise subset of oligonucleotides necessary to assemble a full length gene. The availability of a large validated set of mutually orthogonal primers is therefore a crucial reagent for high-throughput gene synthesis.
View Article and Find Full Text PDFThe sequence of events that initiates T cell signaling is dictated by the specificities and order of activation of the tyrosine kinases that signal downstream of the T cell receptor. Using a platform that combines exhaustive point-mutagenesis of peptide substrates, bacterial surface-display, cell sorting, and deep sequencing, we have defined the specificities of the first two kinases in this pathway, Lck and ZAP-70, for the T cell receptor ζ chain and the scaffold proteins LAT and SLP-76. We find that ZAP-70 selects its substrates by utilizing an electrostatic mechanism that excludes substrates with positively-charged residues and favors LAT and SLP-76 phosphosites that are surrounded by negatively-charged residues.
View Article and Find Full Text PDFStatistical analysis of protein sequences indicates an architecture for natural proteins in which amino acids are engaged in a sparse, hierarchical pattern of interactions in the tertiary structure. This architecture might be a key and distinguishing feature of evolved proteins-a design principle providing not only for foldability and high-performance function but also for robustness to perturbation and the capacity for rapid adaptation to new selection pressures. Here, we describe an approach for systematically testing this design principle for natural-like proteins by (1) computational design of synthetic sequences that gradually add or remove constraints along the hierarchy of interacting residues and (2) experimental testing of the designed sequences for folding and biochemical function.
View Article and Find Full Text PDFJ Trauma Acute Care Surg
April 2012
Allosteric coupling between protein domains is fundamental to many cellular processes. For example, Hsp70 molecular chaperones use ATP binding by their actin-like N-terminal ATPase domain to control substrate interactions in their C-terminal substrate-binding domain, a reaction that is critical for protein folding in cells. Here, we generalize the statistical coupling analysis to simultaneously evaluate co-evolution between protein residues and functional divergence between sequences in protein sub-families.
View Article and Find Full Text PDFThe melting point of triacylglycerides (TAGs) under atmospheric pressure depends on both the fatty acid composition and crystalline structure of the polymorphic state, which are influenced by the temperature treatment history of the TAG. In this contribution, the additional effect of high hydrostatic pressure is described. Samples were placed in a temperature-controlled cell and pressurized up to 450 MPa.
View Article and Find Full Text PDFAn exact copy of the detector model generated for Cyltran was reproduced as an MCNP input file and the detection efficiency was calculated similarly with the methodology used in previous experimental measurements and simulation of a 280 cm(3) HPGe detector. Below 1000 keV the MCNP data correlated to the Cyltran results within 0.5% while above this energy the difference between MCNP and Cyltran increased to about 6% at 4800 keV, depending on the electron cut-off energy.
View Article and Find Full Text PDFStatistical analyses of protein families reveal networks of coevolving amino acids that functionally link distantly positioned functional surfaces. Such linkages suggest a concept for engineering allosteric control into proteins: The intramolecular networks of two proteins could be joined across their surface sites such that the activity of one protein might control the activity of the other. We tested this idea by creating PAS-DHFR, a designed chimeric protein that connects a light-sensing signaling domain from a plant member of the Per/Arnt/Sim (PAS) family of proteins with Escherichia coli dihydrofolate reductase (DHFR).
View Article and Find Full Text PDFThe biodegradation of rapeseed oil methyl ester (RME) in pure and in mixtures with diesel fuel was investigated. Higher ratio of diesel fuel in the mixture resulted in higher count of bacteria. Fungal growth was advanced by higher RME contents.
View Article and Find Full Text PDFUnlabelled: Detection of cell surface molecules labeled by monoclonal or polyclonal antibodies conjugated to a fluorochrome is probably the most widely used application of flow cytometry. This unit contains protocols for tagging monoclonal antibodies with fluorescein, biotin, Texas Red, and phycobiliproteins. In addition, it provides a procedure for preparing a PE-Texas Red tandem conjugate dye that can then be used for antibody conjugation.
View Article and Find Full Text PDFProtein sequences evolve through random mutagenesis with selection for optimal fitness. Cooperative folding into a stable tertiary structure is one aspect of fitness, but evolutionary selection ultimately operates on function, not on structure. In the accompanying paper, we proposed a model for the evolutionary constraint on a small protein interaction module (the WW domain) through application of the SCA, a statistical analysis of multiple sequence alignments.
View Article and Find Full Text PDFClassical studies show that for many proteins, the information required for specifying the tertiary structure is contained in the amino acid sequence. Here, we attempt to define the sequence rules for specifying a protein fold by computationally creating artificial protein sequences using only statistical information encoded in a multiple sequence alignment and no tertiary structure information. Experimental testing of libraries of artificial WW domain sequences shows that a simple statistical energy function capturing coevolution between amino acid residues is necessary and sufficient to specify sequences that fold into native structures.
View Article and Find Full Text PDFBackground: Ramipril may prevent cardiovascular death, myocardial infarction and stroke in patients without evidence of left ventricular dysfunction or heart failure who are at high risk for cardiovascular events. In the present study we assessed the cost-effectiveness of ramipril in patients with an increased risk of cardiovascular events from a third party payer's perspective in Switzerland. In addition, the cost-effectiveness of ramipril in the subgroup of diabetic patients was assessed.
View Article and Find Full Text PDFIntroduction: Immediate accessibility to automated external defibrillators (AED) is recommended for highly frequented public areas. In train terminals and metro stations electromagnetic interference (EMI) is present. In preparation for a public access defibrillation (PAD) programme in this environment possible effects on AED safety and accuracy were studied.
View Article and Find Full Text PDFCrit Rev Food Sci Nutr
September 2005
Waste in the food industry is characterized by a high ratio of product-specific waste. Not only does this mean that the generation of this waste is unavoidable, but also that the amount and kind of waste produced, which consists primarily of the organic residue of processed raw materials, can scarcely be altered if the quality of the finished product is to remain consistent. The utilization and disposal of product-specific waste is difficult, due to its inadequate biological stability, potentially pathogenic nature, high water content, potential for rapid autoxidation, and high level of enzymatic activity.
View Article and Find Full Text PDFObjectives: Emergency services personnel, family members, laypersons or patients often carry and use mobile phones on sites of emergencies. As there are reported effects on implanted pacemakers and cardioverter defibrillators, the influence of digital cellular phones on automated external defibrillators was studied.
Methods: Twelve automated external defibrillator models were bench tested for their correct decision to or not to advise a shock, while being exposed to electromagnetic interference from a handheld cellular phone with 2 W or a portable cellular phone with 8 W transmitting power.