TABLE 2.

Average masses of the major forms of the surfactant proteins measured using MALDI-TOF-MS compared to the theoretical masses based on sequence analysis

Protein sample	Theoretical molecular weight [M+H]+	MALDI-TOF-MS [M+H]+	Difference [Da]
SP-B-1	8691	8738	47
	17381	17558	177
SP-B-2	8691	8705	14
	17381	17424	43
SP-B-3	8691	8710	19
	17381	17424	42
SP-C-1	4201	4198	3
		4217	16
SP-C-2	4201	4201	0
SP-C-3	4201	4201	0