TABLE 1.

Molecular masses (Da) of TF proteins

TF species	Source	Calculateda	MALDI-TOF	Differenceb	SDS-PAGE
		Da	Da	Da	Da
rTF1–243	E. coli	27,423	27,800	377	31,000
rTF1–243“D”	E. coli	27,423	27,800	377	31,000
rTF1–263G	Sf9	29,592	33,196	3,604	37,000
rTF1–263D	Sf9	29,592	30,202	610c	33,000
pTFG	Human placenta	29,592	36,179	6,605	45,000
pTFD	Human placenta	29,592	ND	ND	34,000

^a Calculated from amino acid composition.

^b Difference between calculated mass by amino acid composition and that obtained by MALDI-TOF.

^c This mass was determined on rTF_1–263 deglycosylated with EndoF enzymes.