Table 1.

Effect of selected constituents of pantethine and glutathione on the aggregation of β_L crystallin in the presence of α crystallin

Standard (βL + α)	OD(apparent)
	0.1	0.5	0.9	Max = 1.0
+1 mM pantethine	0.04	0.12	0.32	0.48
+10 mM pathethine	0.01	0.02	0.04	0.18
+1 mM glutathione	0.10	0.50	0.81	0.95
+10 mM glutathione	0.18	0.63	0.81	0.82
+1 mM pantothenic acid	0.16	0.64	1.00	1.00
+1 mM cystamine	0.41	0.75	0.93	0.92
+1 mM β-alanine	0.06	0.21	0.50	0.63
+20 mM GSH	0.29	0.67	1.00	1.14
+20 mM cysteine (-SH)	0.81	1.21	1.43	1.62
+20 mM cysteamine (-SH)	0.26	0.55	0.93	1.10
+20 mM cysteamine (-SPO4)	0.29	0.55	1.00	1.14
+20 mM DTT	0.17	0.57	1.00	2.00

In row 1, the values for the OD during opacification of a standard solution of β_L plus α-crystallin at 60°C without added reagents are listed. Pantothenic acid (1.0 mM) had a weak negative effect and the OD values were higher than the standard. The disulfide cystamine had a very weak positive effect at a concentration of 1.0 mM. The effect of 1.0 mM β-alanine was quite strong, decreasing the OD values at each part of the opacification curve. In comparison with pantethine, 1.0 mM of the disulfide glutathione had weak activity and the OD values were higher than with pantethine. The reduced form of glutathione (GSH) was not protective against aggregation. Tests of several other sulfur compounds, including cysteine, cysteamine, cysteamine-PO₄, and dithiothreitol (DTT), demonstrated that the −SH form of the reagents increased aggregation resulting in OD values that were higher than the standard. All of the studies above were conducted at 60°C. The OD was normalized as described.