REAGENT or RESOURCE	SOURCE	IDENTIFIER
Biological samples
Human plasma	The Environmental Determinants of Diabetes in the Young (TEDDY) study	https://teddy.epi.usf.edu/
Chemicals, peptides, and recombinant proteins
Custom Synthesized Heavy Isotope-Labeled Peptides	New England Peptides, now Vivitide	N/A
4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES)	Sigma - Aldrich	H3375
Acetonitrile, HPLC grade	J.T. Baker	9829–03
Acetonitrile anhydrous	Sigma - Aldrich	271004
Ammonium hydroxide solution	Sigma - Aldrich	338818
Aprotinin	Sigma - Aldrich	A6103
Buffer A for Multiple Affinity Removal LC Column	Agilent	5185–5987
Buffer B for Multiple Affinity Removal LC Column	Agilent	5185–5988
Chloroform	Sigma - Aldrich	C2432
Dithiothreitol	Thermo Scientific	20291
Ethylenediaminetetraacetic acid	Sigma - Aldrich	E7889
Formic acid	Sigma - Aldrich	33015
Iodoacetamide	Thermo Scientific	90034
HPLC Grade Water	J.T. Baker	4218–03
Hydroxylamine Solution 50%	Sigma - Aldrich	467804
Methanol, HPLC grade	Fluka	34966
Sequencing grade modified trypsin	Promega	V5117
Tris (hydroxymethyl)aminomethane hydrochloride pH 8.0	Sigma - Aldrich	T2694
Trifluoroacetic acid	Sigma - Aldrich	91707
Urea	Sigma - Aldrich	U0631
Critical commercial assays
8-plex iTRAQ kit	Applied Biosystems	4390811
Deposited data
Discovery phase mass spectrometry data	MassIVE	MSV000091560
Validation phase mass spectrometry data	MassIVE	MSV000091562
Software and algorithms
R package (v3.2.3)	The R Project for Statistical Computing	https://www.r-project.org/
Decon2LS_V2	Pacific Northwest National Laboratory	https://github.com/PNNL-Comp-Mass-Spec
DTA Refinery	Pacific Northwest National Laboratory	https://github.com/PNNL-Comp-Mass-Spec
MSGF+	University of California – San Diego	https://msgfplus.github.io/
MASIC	Pacific Northwest National Laboratory	https://github.com/PNNL-Comp-Mass-Spec
QC-ART	Pacific Northwest National Laboratory	https://github.com/PNNL-Comp-Mass-Spec
Q4SRM	Pacific Northwest National Laboratory	https://github.com/PNNL-Comp-Mass-Spec
Skyline	University of Washington	https://skyline.ms/
DAVID	National Institutes of Health	https://david.ncifcrf.gov/
Other
Hu-14 4.6 × 100 mm MARS column	Agilent	5188–6558
3-kDa MWCO Amicon centrifugal filters	Millipore	UFC5003BK
Reversed phase tC18 SepPak SPE columns	Waters	WAT054925