Human spermatid-specific thioredoxin-1 (Sptrx-1) is a two-domain protein with oxidizing activity.
Jiménez A, Johansson C, Ljung J, Sagemark J, Berndt KD, Ren B, Tibbelin G, Ladenstein R, Kieselbach T, Holmgren A, et al. FEBS Lett. 2002 Oct 23; 530(1-3):79-84.