[85b] Iodination of tyrosine: Isolation of thyroid peroxidase (pig)

摘要: Publisher Summary This chapter describes the isolation of thyroid peroxidase. Fresh pig thyroids are obtained from slaughterhouse and frozen for 1–21 days at -15°. The glands thawed in 0.9% NaCl solution 4°, trimmed extraneous fat connective tissue, cut into small pieces. minced tissue is washed several times with ice-cold saline to remove as much hemoglobin thyroglobulin possible. All other steps carried out 0–5°. For each 100 g 25 ml 1.0 M Tris-HCl, pH 7.4, added. Spectral properties indicate that peroxidase a hemoprotein an oxidized peak Soret region 412 m μ . enzyme forms cyanide complex exhibiting absorption maximum 425 retains its activity least two months form. When assayed guiacol substrate, it shows optimum 8, when ability oxidize iodide, about 7.