Article Figures & Data
Figures
- Fig. 1.
Amino acid sequences of wt and mutants Tva LDL-A modules in GST fusion constructs. Dashes indicate identical residues; underlines indicate mutated residues. The LDL-A module region is shown as boldface letters. The ability of the wt Tva and Tva mutants to mediate ASLV-A infection was expressed as the number of alkaline phosphatase-positive cells per milliliter of viral stock. The data are from references 21 and 22.
- Fig. 2.
Elution profiles of wt and mutant Tva LDL-A modules by reverse-phase HPLC. The purified proteins were folded in vitro in the presence (A, C, E, G, and I) or absence (B, D, F, H, and J) of calcium and then eluted by reverse-phase HPLC.
- Fig. 3.
Two-dimensional [1H-15N] HSQC spectra of the LDL-A module of Tva and its mutants. The purified15N-labeled proteins were folded in vitro in the presence (A, B, E, F, G, and H) or absence (C and D) of calcium, and two-dimensional [1H-15N] HSQC spectra were acquired either with added calcium (A, C, E, F, G, and H) or with no added calcium (B and D) as described in Materials and Methods. For example, wt +Ca/+Ca (A) indicates that calcium was present in the folding reaction (+Ca/) and with added calcium in NMR analysis (/+Ca).
- Fig. 4.
Calcium titration of the Tva LDL-A module and its mutants by ITC. The Ca2+-binding affinity and enthalpy of binding of wt and mutant Tva LDL-A modules were measured by ITC. D46A and E47A mutant proteins did not display detectable Ca2+binding by ITC (data not shown). x axis, Ca2+/protein molar ratio; y axis, heat release or uptake upon calcium binding. Note that the scales differ among the three panels.
