Table 3. Quantification of glycoprotein surface expression.

The expression levels of each mutant glycoprotein were measured using dual antibody staining on living cells, fluorescent microscopy and image analysis. Results included measurements from cell monolayers. They were obtained from triplicate measurements, from three separate experiments and expressed as intensity mean values for green and red pixels. Expression levels of each mutated protein was compared with that of the corresponding wild type (WT) protein (in bold). Differences in surface expression levels were not statistically significant (P > 0.05).

Glycoprotein	Mutant	Intensity Mean value	Standard error (±)
Haemagglutinin-esterase	HE-SK779/06 (WT)	835.92	11.68
	HE-Mut- Del.	828.75	20.06
Fusion protein	F-Nevis (WT)	518.99	31.42
	F-Mut- R267A	450.19	28.42
	F-Mut- K276A	477.86	18.48
Fusion protein	F-SK779/06 (WT)	284.21	10.47
	F-Mut- G252S	327.83	37.57
	F-Mut- Q266L	290.24	15.59
	F-Mut- Q266P	290.11	17.02
	F-Mut- Ins. 1	290.31	14.12
	F-Mut- Ins. 2	286.98	14.5