Degradation of hepatic zinc-thionein after parenteral zinc administration.
A low-molecular-weight protein, zinc-thionein, a metallothionein, was implicated as having a regulatory function in zinc metabolism. The half-life (t 1/2) of hepatic zinc-thionein was determined by pulse-labelling with either L-[35S] cystine and/or 65Zn. In two experiments with L-[35S]cystine, the t 1/2 of zinc-thionein was 18h and 19h. Most of the soluble 35S-labelled hepatic proteins had a t 1/2 of 4 days. The t 1/2 of zinc-thionein calculated by using 65Zn was 20h. The close similarity between the calculated and measured t 1/2 values for zinc-thionein suggests that release of Zn2+ from zinc-thionein probably occurs simultaneously with degradation of the protein moiety.
D000818:Animals; D003553:Cystine / Q000378:metabolism; D006207:Half-Life; D008099:Liver / Q000378:metabolism*; D008297:Male; D008667:Metalloproteins / Q000378:metabolism*; D008668:Metallothionein / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D015032:Zinc / Q000378:metabolism*
D008667:Metalloproteins; D003553:Cystine; D008668:Metallothionein; D015032:Zinc