During 1979 we propose: 1. In the area of sperm metabolism, to: (a) continue to investigate the function of a new protein discovered in seminal fluid that blocks the penetration of mitochondria by calcium ions; (b) obtain this protein in pure form, and study its physical and chemical properties; (c) continue to search for other means of blocking calcium uptake and, hence, capacitation, in the hope that a practical anti-fertility process might be developed; and (d) investigate the relationship of acetyl carnitine to sperm fertility in bovine and other species. 2. In the area of gluconeogenesis, to: (a) investigate the mechanism of transition metal ion action in the reaction catalyzed by phosphoenolpyruvate carboxykinase; (b) purify the ferroactivator protein from erythrocytes and initiate studies of its possible role in hemoglobin synthesis; and (c) investigate the nature of the interaction of phosphoenolpyruvate carboxykinase and ferroactivator or 3-aminopicolinate.