TABLE 2.

Relationship among the conditions governing the rotavirus TLP-to-DLP transformation and the vesicle membrane CF release reactions^a

[Ca2+] (μM)	Temp (°C)	Salt supplement	TLP-to-DLP transition	CF release
2–1,000	20	±	No	No
2–10	37	Yes	Yes	Yes
>10, <50	37	Yes	Partial	Yes
50–1,000	37	Yes	No	No
2–1,000	37	No	No	No

^aThe TLP-to-DLP transition for the RF strain was studied using both quasielastic light scattering and agarose gel electrophoresis. In CF release experiments, membrane vesicles were incubated at either 20 or 37°C in the membrane buffer supplemented (yes) with 100 mM sorbitol plus 200 mM Tris-Cl or not supplemented (no) in the presence of extra Ca²⁺ at the indicated concentrations. When 200 mM Tris-Cl was not added, 500 mM d-sorbitol was used to maintain iso-osmotic conditions (13). ±, identical results were obtained in either the presence or absence of added salt. Purified TLPs, RF strain, were added directly to the Ca²⁺-treated membrane vesicle incubation medium, as described for Fig. 5.