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Search Publications by: William E. Wallace (Fed)

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Displaying 1 - 25 of 217

An Improved Sample Preparation Method for Protein and Peptide Identification from Human Hair

November 27, 2023
Author(s)
Zheng Zhang, William E. Wallace, Guanghui Wang, Meghan Burke Harris, Yi Liu, Sergey Sheetlin, Stephen E. Stein
A fast and sensitive Direct Extraction (DE) method developed in our group can efficiently extract proteins in 30 min from a 5 cm-long hair strand. Previously we coupled DE to downstream analysis using gel electrophoresis followed by in-gel digestion, which

Inferring the nominal molecular mass of an analyte from its electron ionization mass spectrum

August 23, 2023
Author(s)
Arun Moorthy, Anthony J. Kearsley, William Mallard, William E. Wallace, Stephen E. Stein
The performance of three algorithms for predicting nominal molecular mass from an analyte's electron ionization mass spectrum is presented. The Peak Interpretation Method (PIM) attempts to quantify the likelihood that a molecular ion peak is contained in

On the challenge of unambiguous identification of fentanyl analogs: exploring measurement diversity using standard reference mass spectral libraries

July 11, 2023
Author(s)
Arun Moorthy, Edward Erisman, Anthony J. Kearsley, Yuxue Liang, Edward Sisco, William E. Wallace
Fentanyl analogs are a class of designer drugs that are particularly challenging to unambiguously identify due to the mass spectral and retention time similarities of unique compounds. In this paper, we use agglomerative hierarchical clustering to explore

Comprehensive Analysis of Tryptic Peptides Arising from Disulfide Linkages in NISTmAb and Their Use for Developing a Mass Spectral Library

June 22, 2021
Author(s)
Qian Dong, Xinjian Yan, Yuxue Liang, Sanford Markey, Sergey L. Sheetlin, Concepcion Remoroza, William E. Wallace, Stephen Stein
This work presents methods for identifying and then creating a mass spectral library for disulfide-linked peptides originating from the NISTmAb. Analysis involved both partially- reduced and non-reduced proteins under neutral and weakly basic conditions

Mass Spectral Library of Acylcarnitines Derived from Human Urine

April 8, 2020
Author(s)
Xinjian Yan, Sanford Markey, Ramesh Marupaka, Qian Dong, Brian T. Cooper, Yuri Mirokhin, William E. Wallace, Stephen Stein
We describe the creation of a mass spectral library of acylcarnitines and conjugated acylcarnitines from the LC–MS/MS analysis of six NIST urine reference materials. To recognize acylcarnitines, we conducted in-depth analyses of fragmentation patterns of

Sensitive Method for the Confident Identification of Genetically Variant Peptides in Human Hair

October 31, 2019
Author(s)
Zheng Zhang, Meghan Burke, William E. Wallace, Yuxue Liang, Sergey L. Sheetlin, Yuri Mirokhin, Dmitrii Tchekhovskoi, Stephen Stein
Recent reports have demonstrated that genetically variant peptides (GVPs) derived from human hair shaft proteins can be used to differentiate individuals of different biogeographic origin (Parker, G.J.; et al. PLos One. 2016, e0160653). We report a direct

Standard Reference Data Workshop Report

June 12, 2018
Author(s)
Debra L. Kaiser, Neil Alderoty, Richard R. Cavanagh, Barbara Guttman, Robert J. Hanisch, Adam G. Morey, Jeanita Pritchett, Yuri Ralchenko, Stacy S. Schuur, William E. Wallace
On October 17, 2017, the ODI sponsored a day-long Standard Reference Data Workshop. More than 120 NIST staff members and associates from four NIST laboratories and three offices registered for this workshop. The workshop format consisted of presentations

Combining fragment ion and neutral loss matching during mass spectral library searching: A new general-purpose algorithm applicable to illicit drug identification

November 20, 2017
Author(s)
Arun S. Moorthy, William E. Wallace, Anthony J. Kearsley, Dmitrii V. Tchekhovskoi, Stephen E. Stein
A mass spectral library search algorithm that identifies compounds that differ from library compounds by a single ‘inert’ structural component is described. This algorithm, the Hybrid Similarity Search, generates a similarity score based on matching both

Mass Spectral Library Quality Assurance by Inter-Library Comparison

April 2, 2017
Author(s)
William E. Wallace, Weihua Ji, Dmitrii V. Tchekhovskoi, Karen W. Phinney, Stephen E. Stein
A method to discover and correct errors in mass spectral libraries is described. Comparing across a set of highly curated reference libraries compounds that have the same chemical structure quickly identifies entries that are outliers. In cases where three