Myostatin as a mediator of sarcopenia versus homeostatic regulator of muscle mass: insights using a new mass spectrometry-based assay

Table 1 Peptides, transitions, and instrument parameters for myostatin, propeptide, GASP-1, and FLRG

	Parent mass	Product mass	Collision energy	S-lens
Myostatin
*IPAMVVDR*	450.68	619.33	19	123
	450.68	690.40	17	123
	450.68	787.52	17	123
IIYGKIPAMV*VDRCGCS	453.65	619.44	19	123
	453.65	690.50	18	123
	453.65	763.65	16	123
EQIIYGK	425.66	480.31	13	86
	425.66	593.47	14	86
EQ*IIYGK	429.14	480.35	13	86
	429.14	600.43	14	86
Propeptide
*TVLQNWLK*	501.18	560.32	18	131
	501.18	688.60	18	131
	501.18	801.78	18	131
SIDVKTVLQNW*LKQPESN	504.75	567.25	19	131
	504.75	695.42	17	131
	504.75	808.65	15	131
ELIDQYDVQR	639.70	680.42	21	132
	639.70	808.50	20	132
	639.70	923.77	20	132
ELIDQYD*VQR	642.92	686.48	20	132
	642.92	814.36	22	132
	642.92	929.43	21	132
GASP-1
*ADFPLSVVR*	502.28	670.53	18	131
AGVLRADFPLSV*VRGHQAA	505.23	579.46	19	131
	505.23	676.64	16	131
VSELTEEPDSGR	659.81	789.36	20	168
	659.81	890.51	21	168
VSELTEE*PDSGR	662.73	795.31	21	168
	662.73	896.60	21	168
FLRG
*LQVCGSDGATYR*	663.78	826.30	23	168
	663.78	986.34	21	168
	663.78	1085.46	21	168
GLPARLQVCGSDGATYRDECEL	666.78	832.56	24	168
	666.78	992.69	23	168
	666.78	1092.15	22	168

Target peptides for each protein, parent and product ion masses as well as MS parameters and transitions used quantitation of each protein are indicated in bold and/or italics. Labeled amino acids (¹³C₅ ¹⁵N-V, ¹³C₆ ¹⁵N-L, ¹³C₅ ¹⁵N-P_, ¹³C₂ ¹⁵N-G, and ¹³C₃-A) are indicated by the asterisk

ISSN: 2044-5040