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PubMed · 8179621

Annexins possess functionally distinguishable Ca2+ and phospholipid binding domains.

J D Ernst·A Mall·G Chew
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Abstract

All annexins bind Ca2+ and phospholipids, although individual annexins differ markedly in their affinities for these ligands. Annexin I binds phosphatidylserine (PS) at lower [Ca2+] than annexin V, while annexin V exhibits a higher affinity for PS than does annexin I. To identify the structural determinants of these properties, we characterized a series of chimeric annexins. A chimera containing repeat 1 of annexin V used to repeats 2, 3, and 4 of annexin I exhibited a Ca2+ requirement for PS binding close to that of annexin I, while chimeras containing repeat 1 of annexin I fused to repeats 2, 3, and 4 of annexin V required higher [Ca2+], similar to that of annexin V. In contrast, the overall affinity for PS vesicles was determined by the source of repeat 1. The chimera that contained repeat 1 of annexin V exhibited a high affinity for PS, while a chimera that contained repeat 1 of annexin I had a low affinity for PS similar to that of annexin I. We conclude that the [Ca2+] requirement for phospholipid binding and the overall phospholipid affinity of annexins are determined by distinct domains.

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AnnexinsBase SequenceBinding SitesCalciumDNA PrimersHumansMolecular Sequence DataPhosphatidylserinesPoint MutationRecombinant Fusion ProteinsRepetitive Sequences, Nucleic AcidJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

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J D Ernst, A Mall, G Chew. 1994-04-29. Annexins possess functionally distinguishable Ca2+ and phospholipid binding domains.. https://doi.org/10.1006/bbrc.1994.1531

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