Predicting the composition of red wine blends using an array of multicomponent Peptide-based sensors

Multiplexing the Quantitation of MAP Kinase Activities Using Differential Sensing

Protein kinases are therapeutic targets for many human diseases, but the lack of user-friendly quantitative assays limits the ability to follow the activities of numerous kinases at once (multiplexing). To develop such an assay, we report an array of sulfonamido-oxine (SOX)-labeled peptides showing cross-reactivity to different mitogen-activated protein kinases (MAPKs) for use in a differential sensing scheme. We first verified using linear discriminant analysis that the array could differentiate MAPK isoforms. Then, using principal component analysis, the array was optimized based on the discrimination imparted by each SOX-peptide. Next, the activity of individual MAPK families in ternary mixtures was quantified by support vector machine regression. Finally, we multiplexed the quantification of three MAPK families using partial least squares regression in A549 cell lysates, which has possible interference from other kinase classes. Thus, our method simultaneously quantifies the activity of multiple kinases. The technique could be applied to other protein kinase families and the monitoring of diseases.

Combination of two analytical techniques improves wine classification by Vineyard, Region, and vintage

Three important wine parameters: vineyard, region, and vintage year, were evaluated using fifteen Vitis vinifera L. 'Pinot noir' wines derived from the same scion clone (Pinot noir 667). These wines were produced from two vintage years (2015 and 2016) and eight different regions along the Pacific Coast of the United States. We successfully improved the classification of the selected Pinot noir wines by combining an untargeted 1D ¹H NMR analysis with a targeted peptide based differential sensing array. NMR spectroscopy was used to evaluate the chemical fingerprint of the wines, whereas the peptide-based sensing array is known to mimic the senses of taste, smell, and palate texture by characterizing the phenolic profile. Multivariate and univariate statistical analyses of the combined NMR and differential sensing array dataset classified the genetically identical Pinot noir wines on the basis of distinctive metabolic signatures associated with the region of growth, vineyard, and vintage year.

Multi-Institution Research and Education Collaboration Identifies New Antimicrobial Compounds

New antibiotics are urgently needed to address increasing rates of multidrug resistant infections. Seventy-six diversely functionalized compounds, comprising five structural scaffolds, were synthesized and tested for their ability to inhibit microbial growth. Twenty-six compounds showed activity in the primary phenotypic screen at the Community for Open Antimicrobial Drug Discovery (CO-ADD). Follow-up testing of active molecules confirmed that two unnatural dipeptides inhibit the growth of Cryptococcus neoformans with a minimum inhibitory concentration (MIC) ≤ 8 μg/mL. Syntheses were carried out by undergraduate students at five schools implementing Distributed Drug Discovery (D3) programs. This report showcases that a collaborative research and educational process is a powerful approach to discover new molecules inhibiting microbial growth. Educational gains for students engaged in this project are highlighted in parallel to the research advances. Aspects of D3 that contribute to its success, including an emphasis on reproducibility of procedures, are discussed to underscore the power of this approach to solve important research problems and to inform other coupled chemical biology research and teaching endeavors.

Detection of anabolic steroids via cyclodextrin-promoted fluorescence modulation

Reported herein is the detection of anabolic steroids through the use of cyclodextrin-promoted interactions between the analyte of interest and a high quantum yield fluorophore, which lead to measurable, analyte-specific changes in the fluorophore emission signal. By using a variety of β-cyclodextrin derivatives (unmodified β-cyclodextrin, methyl-β-cyclodextrin, and 2-hydroxypropyl-β-cyclodextrin) in combination with high quantum yield fluorophore rhodamine 6G, we detected five anabolic steroid analytes with 100% differentiation between structurally similar analytes and micromolar level limits of detection. Overall, these results show significant potential in the development of practical, fluorescence-based steroid detection devices.

Computer analysis of the sensory qualities of red wines as a method to optimize their blend formulation

Three high quality red wines – Merlot, Cabernet Sauvignon and Pinot Noir – were used for development of an optimized formulation of a new blended wine called Zvezda Kubani (“The Star of Kuban”). The experimental plan was implemented with the mixture designs and triangular surfaces module in the STATISTICA package. According to the experimental plan, we made and studied 31 variants of wines, including 3 monovariants, 3 mixtures of 2 wines and 25 mixtures of 3 wines. In addition, highly qualified specialists have studied the changes in the mixtures according to the results of a sensory assessment to model the connection between the sensory perception of wine mixtures and the new blended wine formulation. As a result, we developed a mathematically proved formulation of a new blended wine, Zvezda Kubani, containing 48% Merlot, 35% Cabernet Sauvignon and 17% Pinot Noir. The experimental verification of the suggested composition of the blend proved to be a strong indicator of the experts' sensory assessment.

Peptoids advance multidisciplinary research and undergraduate education in parallel: Sequence effects on conformation and lipid interactions

Peptoids are versatile peptidomimetic molecules with wide-ranging applications from drug discovery to materials science. An understanding of peptoid sequence features that contribute to both their three-dimensional structures and their interactions with lipids will expand functions of peptoids in varied fields. Furthermore, these topics capture the enthusiasm of undergraduate students who prepare and study diverse peptoids in laboratory coursework and/or in faculty led research. Here, we present the synthesis and study of 21 peptoids with varied functionality, including 19 tripeptoids and 2 longer oligomers. We observed differences in fluorescence spectral features for 10 of the tripeptoids that correlated with peptoid flexibility and relative positioning of chromophores. Interactions of representative peptoids with sonicated glycerophospholipid vesicles were also evaluated using fluorescence spectroscopy. We observed evidence of conformational changes effected by lipids for select peptoids. We also summarize our experiences engaging students in peptoid-based projects to advance both research and undergraduate educational objectives in parallel.

A Simple Optoelectronic Tongue Discriminates Amino Acids

A self-assembled nine-element optoelectronic tongue consisting of a positively charged water-soluble poly(para-phenyleneethynylene) and three metal ions (Fe²⁺ , Co²⁺ , and Cu²⁺ ) at three different pH values (7, 10, and 13) discriminates all of the 20 natural amino acids in water. Unknown identification was not ideal. Addition of a highly positively charged green fluorescent protein in the presence of Fe²⁺ , Co²⁺ , and Cu²⁺ increased the unknown identification to above 86 %. Linear discriminant analysis (LDA) orders the responses according to the amino acid type, that is, hydrophobic, polar, anionic, or cationic.

Differentiation and Identification of Cachaça Wood Extracts Using Peptide-Based Receptors and Multivariate Data Analysis

It is becoming increasingly important to differentiate complex mixtures, especially in forensics. Cachaça, the most popular alcoholic beverage in Brazil, is made from distilled and fermented sugar cane juice. It contains a mixture of naturally occurring polyphenols known as tannins, whose composition is dictated by the type of wood used to age the beverage. These tannins can be differentiated in an Indicator Displacement Assay (IDA) using peptide-based ternary sensing ensembles. This investigation demonstrates a technique for fingerprinting the identity of the woods used to age cachaças. Unknown cachaça samples were tested against a training set of Brazilian woods in addition to oaks from different countries. Results obtained from the analysis showed that 62.5% of the samples were correctly identified. Furthermore, four samples anonymously added to the pool of unknowns from the training set were identified with 100% accuracy, emphasizing both the promising results obtained from this method of differentiation and the importance of analyzing same-age samples.

Fluorescent sensing arrays for cations and anions

A review of fluorescent sensing arrays for anions and cations, highlighting promising strategies and directions for future research.