Table 2. Summary of FRET analyses demonstrating interactions between MBP-II^Glc-CFP and MBP-II^Glc-YFP fused proteins of peaks 1 and 2.

Preparation	Mixing condition	CFP/YFP ratio of fused proteins	Protein concentration (mg/ml) of the CFP and YFP fused protein mixtures	emission at λ 476/emission at λ 526 for CFP (control)	emission at λ 476/emission at λ 526 for CFP of corrected CFP (CFP in the CFP and YFP mixture)a	FRET result (arbitrary FRET intensities)
Peak 1	Purified CFP and YFP fused proteins were mixed after purification.	1	0.71	1.91	1.85	Nearly no FRET
			0.5	1.9	1.82
		1/6	4.93	1.92	1.99
		1/10	4.93	1.93	2.05
	Crude CFP and YFP fused proteins were mixed, and then purified.	1/6	1.87	1.87	1.85	Nearly no FRET
			0.94	1.79	1.94
		1/10	1.85	1.88	1.79
			0.93	1.87	1.77
	Crude CFP and YFP fused proteins were mixed, detergent treated, purified and then analyzed.	1/6	2.2	1.96	1.24	Presence of FRET (36.7%)
		1/10	2.49	1.96	1.18	Presence of FRET (39.8%)
		1/20	2.15	1.97	1.08	Presence of FRET (45.2%)
	Purified CFP and YFP fused proteins were mixed, detergent treated and analyzed.	1/6	4.69	1.85	1.97	No FRET
		1/10	4.69	1.84	1.94
Peak 2	Purified CFP and YFP fused proteins were mixed after purification.	1	0.51	1.9	1.77	Nearly no FRET
		1/6	1.64	1.88	1.97
			4.85	1.93	1.99
		1/21	0.55	1.87	2.8
	Crude CFP and YFP fused proteins were mixed and then purified.	1/10	1	1.88	1.22	Presence of FRET (35.1)
		1/16	0.61	1.91	1.46	Presence of FRET (23.6)
Peak1/Peak 2	Crude CFP and YFP fused proteins from peaks 2 & 1, respectively, were mixed and then purified.	1/6	8.4	1.93	1.54	Presence of FRET (20.2)
		1/3	11.7	1.89	1.34	Presence of FRET (29.1)

^aThe presence of FRET was indicated by a decrease (>10%) in the ratio of emission at λ476/emission at λ 526 of corrected CFP (CFP in the CFP and YFP mixture after subtraction of the contribution due to YFP) as compared to the ratio of emission at λ476/emission at λ 526 for CFP alone (control).