Calcium-dependent structural changes in human reticulocalbin-1

In this study, we established a new bacterial expression and purification procedure for hRCN1. We observed that hRCN1 binds Ca2+ in a cooperative manner and the Ca2+ binding caused an increase in the α-helix content of hRCN1. On the other hand, hRCN1 did not change the structure with Mg2+ loading. hRCN1 is a monomeric protein, and its overall structure became more compact upon Ca2+ binding, as revealed by gel-filtration column chromatography and small-angle X-ray scattering. This is the first report of conformational changes in the CREC family upon Ca2+ binding. Our data suggest that CREC family member interactions with target proteins are regulated in the secretory pathway by conformational changes upon Ca2+ binding.

Source: Journal of Biochemistry - April 27, 2014 Category: Biochemistry Authors: Suzuki, N., Ban, S., Itoh, E., Chen, S., Imai, F. L., Sawano, Y., Miyakawa, T., Tanokura, M., Yonezawa, N. Tags: Regular Papers Source Type: research