thus , to address this problem , disulfide bonds of ribonuclease-a and lysozyme were reductively cleaved under denaturing conditions , and the resulting 7-8 sulfhydryl groups were treated with a new sulfhydryl group reagent containing selenium , 6,6'-diselenobis ( 3-nitrobenzoic acid ) , to give proteins containing covalently attached selenium in the form of selenenyl sulfides .
C0036581
selenium
C0074281
selenium