Human spermatid-specific thioredoxin-1 (Sptrx-1) is a two-domain protein with oxidizing activity
2002 (English)In: FEBS Letters, ISSN 0014-5793, E-ISSN 1873-3468, Vol. 530, no 1-3, 79-84 p.Article in journal (Refereed) Published
Spermatid-specific thioredoxin-1 (Sptrx-1) is the first member of the thioredoxin family of proteins with a tissue-specific expression pattern, found exclusively in the tail of elongating spermatids and spermatozoa. We describe here further biochemical characterization of human Sptrx-1 protein structure and enzymatic activity. In gel filtration chromatography human Sptrx-1 eluates as a 400 kDa protein consistent with either an oligomeric form, not maintained by intermolecular disulfide bonding, and/or a highly asymmetrical structure. Analysis of circular dichroism spectra of fragments 1-360 and 361-469 and comparison to spectra of full-length Sptrx-1 supports a two-domain organization with a largely unstructured N-terminal domain and a folded thioredoxin-like C-terminal domain. Functionally, Sptrx-1 behaves as an oxidant in vitro when using selenite, but not oxidized glutathione, as electron acceptor. This oxidizing enzymatic activity suggests that Sptrx-1 might govern the stabilization (by disulfide cross-linking) of the different structures in the developing tail of spermatids and spermatozoa.
Place, publisher, year, edition, pages
2002. Vol. 530, no 1-3, 79-84 p.
Biochemistry and Molecular Biology Cell Biology
IdentifiersURN: urn:nbn:se:sh:diva-15778DOI: 10.1016/S0014-5793(02)03417-8ISI: 000178856900015PubMedID: 12387870ScopusID: 2-s2.0-18644381177OAI: oai:DiVA.org:sh-15778DiVA: diva2:508436