标题：Characteristics of Polarographic Catalytic Waves Observed with Bovine-Serum Albumin: Effects of Type of Buffers, pH, Ionic Strength, Calcium, and Tetraalkyl Salts
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1974
卷号：71
期号：5
页码：2072-2076
DOI：10.1073/pnas.71.5.2072
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Brdi[c]ka currents observed with bovineserum albumin in ammoniacal buffers with Co(III) and Co(II) as catalysts are identical only when the concentrations of ammonia and ammonium chloride are at least 0.5 M and 0.05 M, respectively. When these conditions are not fulfilled, and in all Tris and borate buffers, the pattern of Brdi[c]ka currents with Co(III) are quite different from those with Co(II). In such buffers the Co(II) is rapidly reduced at potentials slightly more negative than that at which the Brdi[c]ka current attains a peak value. In several such buffers the Brdi[c]ka current may then reduced to zero. In buffers of low ionic strength (about 0.02) and with Co(III), small concentrations of alkali salts greatly increase Brdi[c]ka currents. When the ionic strength of the buffer is 0.05 M or greater, the effect of alkali salts (up to 0.2 M) is small, but even traces of calcium have a large effect in all buffers with Co(III) as catalyst. Evidence is presented that in the presence of calcium all 17 disulfide groups in bovine-serum albumin are reduced at the dropping mercury electrode. Traces of tetraalkyl salts greatly increase Brdi[c]ka currents, but the effects is quite different from that of calcium.
