In sum, proteins with high levels of cystine can help in maintaining mercaptalbumin levels in rats fed with a low-protein diet.
Journal Reference:
Kuwahata M, Kobayashi Y, Wada Y, Aoi W, Kido Y. DIETARY CYSTINE IS IMPORTANT TO MAINTAIN PLASMA MERCAPTALBUMIN LEVELS IN RATS FED LOW-PROTEIN DIETS. Nutrition Research. August 2018;56:79–89. DOI: 10.1016/j.nutres.2018.04.019