Bartholeyns J, Wang D, Blackburn P, Wilson G, Moore S, Stein W H
Int J Pept Protein Res. 1977;10(2):172-5. doi: 10.1111/j.1399-3011.1977.tb02792.x.
A recent conclusion that beef pancreas contained a molecular species of ribonuclease with intrinsically high activity at pH 4.5 has been found to be incorrect. The particular assay used in the earlier experiments gives anomalous results at acid pH in the presence of low concentrations of ions such as phosphate which was used during the fractionation. By turning to the more widely employed form of the perchloric acid precipitation assay, interference is avoided and the ribonuclease in beef pancreas is confirmed as consisting almost completely of the molecular species well-characterized as ribonuclease A. The clarification of the assay question permits a clear interpretation of the results of each step of the chromatographic purification procedure that led to the initial conclusion, including an artifact that arose when gel filtration was attempted with distilled water rather than with buffer.
最近得出的关于牛胰腺含有一种在pH 4.5时具有内在高活性的核糖核酸酶分子种类的结论被发现是错误的。早期实验中使用的特定测定方法，在存在低浓度离子（如分级分离过程中使用的磷酸盐）的酸性pH条件下会给出异常结果。通过采用更广泛使用的高氯酸沉淀测定形式，避免了干扰，并且证实牛胰腺中的核糖核酸酶几乎完全由被充分表征为核糖核酸酶A的分子种类组成。测定问题的澄清使得能够清楚地解释导致最初结论的色谱纯化程序每一步的结果，包括在用蒸馏水而非缓冲液进行凝胶过滤时出现的假象。
