We report the separation of 4-(3-pyridinylmethylaminocarboxypropyl) phenylthiohydantoins by microbore reverse-phase high-performance liquid chromatography and their detection by on-line electrospray ionization mass spectrometry. These compounds are the products of the chemical stepwise degradation of polypeptides using 4-(3-pyridinylmethylaminocarboxypropyl) phenyl isothiocyanate. We describe chromatographic conditions for on-column concentration of the analytes and for baseline separation of the isobaric amino acid derivatives of leucine and isoleucine. A commercially available protein sequencer was readily interfaced with the described analytical system and used for adsorptive sequence analysis of a panel of synthetic peptides containing collectively all 20 naturally occurring amino acids. On-line mass analysis of derivatives generated by automated sequencing confirmed that the derivatives were of the predicted mass and were detectable at comparable signal strength and sensitivity. Finally, we demonstrate that the additional selectivity in data interpretation provided by mass analysis dramatically improves the signal-to-noise ratio and therefore enhances the ability to conclusively interpret protein and peptide sequence data.
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http://dx.doi.org/10.1006/abio.1995.1053 | DOI Listing |
Anal Chim Acta
May 2025
Department of Human Sciences, The Ohio State University, USA; James Comprehensive Cancer Center, The Ohio State University, Columbus, OH, 43210, USA. Electronic address:
Background: The imperative need for early cancer detection, which is crucial for improved survival rates in many severe cancers such as lung cancer, remains challenging due to the lack of reliable early-diagnosis technologies and robust biomarkers. To address this gap, innovative screening platforms are essential to unveil the chemical signatures of lung cancer and its treatments. It is established that the oxidative tumor environment induces alterations in host metabolic processes and influences endogenous volatile synthesis.
View Article and Find Full Text PDFZhong Nan Da Xue Xue Bao Yi Xue Ban
October 2024
Department of Pharmaceutical Engineering, Chemistry and Chemical Engineering, Central South University, Changsha 410083.
Objectives: Small interfering RNA (siRNA) can silence disease-related genes through sequence-specific RNA interference (RNAi). Cationic lipid-based liposomes effectively deliver nucleic acids into the cytoplasm but often exhibit significant toxicity. This study aims to synthesize a novel ionizable lipid, Nε-laruoyl-lysine amide (LKA), from natural amino acids, constructed LKA-based liposomes, and perform physicochemical characterization and cell-based experiments to systematically evaluate the potential of these ionizable lipid-based liposomes for nucleic acid delivery.
View Article and Find Full Text PDFPoult Sci
March 2025
Meat Proteomics Lab, ICAR-National Meat Research Institute, Chengicherla, Hyderabad, Telangana 500092, India.
The study investigated gelatin extraction from chicken skin-head-feet (SHF) blend using conventional and ultrasound-assisted methods with food-grade acetic and citric acids. Ultrasound pretreatment was introduced as an intervention in the extraction process, eliminating the need for alkali hydrolysis and significantly reducing the processing time. The gelatin yield, gel clarity, textural parameters, and functional properties were noticeably improved with ultrasound pretreatment.
View Article and Find Full Text PDFSTAR Protoc
March 2025
Faculty of Data Science and Information Technology, INTI International University, Nilai 71800, Malaysia.
Colostrum and milk from dairy sources consist of whey, casein, and fat, which have notable pharmacological properties due to their proteins and peptides. Here, we present a protocol for isolating, simulating in vitro gastrointestinal digestion, and fractionating colostrum and milk hydrolysates from any dairy source. We also describe steps for nano-liquid chromatography-electrospray ionization-tandem mass spectrometry (nano-LC-ESI-MS/MS) identification of proteins and peptides and in silico system biology-based profiling of the proteins and peptides present in the hydrolysates.
View Article and Find Full Text PDFJ Allergy Clin Immunol
March 2025
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minn. Electronic address:
Background: The few reported patients with pathogenic IRF8 variants have manifested 2 distinct phenotypes: (1) an autosomal recessive severe immunodeficiency with significant neutrophilia and absence of or significant decrease in monocytes and dendritic cells and (2) a dominant-negative form with only a decrease in conventional type 2 dendritic cells (cDC2s) and susceptibility to mycobacterial disease.
Objectives: Genetic testing of a child with persistent EBV viremia identified a novel IRF8 variant: c.1279dupT (p.
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