Pituitary lactogenic hormone. XXIX. Reaction of tetranitromethane with ovine hormone

Reaction of bovine and ovine pituitary growth hormones with tetranitromethane

“…This retardation may be due to absorption of the protein onto the gel or to a slight shift in equilibrium toward the monomeric form. The final yield of the major product was high (56% for nitrotyrosyl-BGH, 59% for nitrotyrosyl-SGH) as compared to the yields following nitration of human growth hormone (Ma et al, 1971;Maddaiah et al, 1972) and ovine lactogenic hormone (Ma et al, 1970) at 25°. Experiments conducted on BGH at 25°also lead to the'isolation of substantially less dimer material, i.e., 25%.…”

Reactions of tetranitromethane. Mechanism of the reaction of tetranitromethane with pseudo acids

“…Therefore, we cautioned that the reactions of C(N02)4 with proteins could lead to radical coupling of proteins as a serious side reaction. Since then there has been numerous reports of the formation of cross-linked monomers, dimers, and higher polymers of proteins caused by treatment with C(N02)4 (Doyle et al, 1968;Bello, 1969;Boesel and Carpenter, 1970;Vincent et al, 1970;Ma et al, 1970;Williams and Lowe, 1971;Boyd and Smith, 1971).…”