Table 2. Quantitative distribution of MBP_83–99 breakdown products.

Peak	Peptide sequence	Protease	Control cells, %	Autophagic cells, %
1	IVTPRTP	AEP	21.5	12.6
2	NIVTPRTP	Cat S/L	3.3	2.2
3	FKNIVTPRTP	Cat D	2.2	3.2
4	ENPVVHF	Cat D	7.0	5.0
5	NPVVHFFKN	—	2.5	0.5
6	FFKNIVTPRTP	Cat S/L	1.4	1.2
7	ENPVVHFFKN	AEP	17.2	12.9
8	ENPVVHFFK	Cat S/L	3.6	1.5
9	VVHFFKNIVTPRTP	—	1.3	1.2
	PVVHFFKNIVTPRT
10	NPVVHFFKNIVTPRTP	—	3.2	1.1
11	ENPVVHFFKNIVTPRTP	Undigested	36.6	58.7

Breakdown products were quantified by their peak heights in the RP-HPLC chromatogram. The total amount of identified peptides was set to 100%. Shown are the differences between control cells and cells undergoing 24 h of autophagy and the lysosomal proteases, which are known to be responsible for the generation of the corresponding fragments (18).