An Insight of S‐Nitrosylation of Human GIF

Abstract

AbstractNeural growth inhibitory factor (GIF), a member of metallothionein family (metallothionein‐3, MT3), was well known by its distinct neural growth inhibitory activity, which is not shown by other MT isoforms. However, till now, people still did not know clearly how GIF exerts its biological functions. Since it has been reported that GIF might serve as NO scavenger and was related to the release of zinc, our study was focused on the interaction of GIF and NO. By studying the reactions of human GIF and human MT1g with SNOC–a type of NO donor, it was found that GIF was more reactive than MT‐1g toward SNOC. In order to further figure out if the high reactivity of GIF in this reaction resulted from the acid‐base catalysis, several mutants were constructed: E23K, E41G/E43A, E23K/E41G/E43A. By studying their basic properties and the reactions toward SNOC, it was found that the S‐nitrosylation of GIF was not only related to the acid‐base catalysis, but also to the accessibility of metal‐thiolate clusters.