Figure 3
From: Quantifying extracellular matrix turnover in human lung scaffold cultures
Stable isotope labeling of cells in native tissue scaffolds. (A) Decellularized scaffolds are seeded with cells and cultured in media containing heavy lysine (*Lys-6). All newly produced proteins contain heavy lysines (blue lines) whereas original scaffold proteins only contain non-labeled lysines (red lines). (B) Mass spectrometry analysis of the trypsin digested proteins produced doublet peaks separated by a discrete mass difference between labeled (blue bars) and non-labelled proteins (red-bars). The ratio between new peptides derived from newly synthesized proteins (new) and scaffold proteins (old) changes between time points as the tissue is remodeled. (C) A weighted scatter plot where a gradual accumulation of new protein is shown by an increase in point size with a corresponding shift in the ratio between new protein and old scaffold protein.
