PXD015698

PXD015698 is an original dataset announced via ProteomeXchange.

Title	Uniformly 15N-Labeled Recombinant Ricin A-chain as an Internal Retention Time Standard for Increased Confidence in Forensic Identification of Ricin by Untargeted Nanoflow Liquid Chromatog-raphy-Tandem Mass Spectrometry
Description	Ricin, a toxic protein from the castor plant, is of forensic and biosecurity interest because of its high toxicity and common occurrence in crimes and attempted crimes. Qualitative methods to detect ricin are therefore needed. Untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomics methods are well-suited because of their high speci-ficity. Specificity in LC-MS/MS comes from both the LC and MS components. However, modern untargeted proteomics methods often use nanoflow LC, which has less reproducible retention times than standard-flow LC, making it challenging to use retention time as a point of identification in a forensic assay. We address this challenge by using retention times rela-tive to a standard, namely uniformly 15N–labeled ricin A-chain produced recombinantly in a bacterial expression system. This material, added as an internal standard prior to trypsin digestion, produces a stable isotope labeled standard for every ricin tryptic peptide in the sample. We show that the MS signals for 15N and natural isotopic abundance ricin peptides are distinct, with mass shifts that correspond to the numbers of nitrogen atoms in each peptide or fragment. We also show that, as expected, labeled and unlabeled peptides coelute, with relative retention time differences of less than 0.2%.
HostingRepository	PRIDE
AnnounceDate	2020-07-16
AnnouncementXML	Submission_2020-07-15_17:51:21.xml
DigitalObjectIdentifier	https://dx.doi.org/10.6019/PXD015698
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Supported dataset by repository
PrimarySubmitter	Eric Merkley
SpeciesList	scientific name: Ricinus communis (Castor bean); NCBI TaxID: 3988;
ModificationList	Oxidation; Carbamidomethyl
Instrument	Q Exactive

Revision	Datetime	Status	ChangeLog Entry
0	2019-10-04 02:00:05	ID requested
⏵ 1	2020-07-15 17:51:22	announced

Dataset with its publication pending

submitter keyword: Ricin

forensics

retention time

standards, stable isotope labels

nitrogen-15

Eric Merkley
contact affiliation	Chemical and Biological Signatures Group, Pacific Northwest National Laboratory
contact email	eric.merkley@pnnl.gov
lab head
Eric Merkley
contact affiliation	Pacific Northwest National Laboratory
contact email	eric.merkley@pnnl.gov
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD015698
     1. Label: PRIDE project
     2. Name: Uniformly 15N-Labeled Recombinant Ricin A-chain as an Internal Retention Time Standard for Increased Confidence in Forensic Identification of Ricin by Untargeted Nanoflow Liquid Chromatog-raphy-Tandem Mass Spectrometry