Goi G, Fabi A, Lombardo A, Bairati C, Bovati L, Burlina A B, Agosti S, Serio C, Tettamanti G
Department of Medical Chemistry, Medical School, University of Milan, Italy.
Clin Chim Acta. 1989 Feb 22;179(3):327-40. doi: 10.1016/0009-8981(89)90096-x.
beta-D-N-Acetylglucosaminidase isozymes were separated and assayed in the plasma of control healthy individuals and pregnant women by an automated method consisting in chromatofocusing on polybuffer exchanger PBE-94 column, flow-through fluorimetric determination of activity and computer assisted quantification. Under the established optimal conditions the method fractionated beta-D-N-acetylglucosaminidase into four isozymes. A, I2, I1 and B, with the analytical coefficients of variation of 1.8, 2.2, 6.4 and 4.1%, respectively. Duration of a single analysis was 25 min including washing, and 10-15 successive runs could be performed on the same column with good reproducibility. A linear activity response was observed from 1-5 microliters of plasma (depending on the individual isozyme) to 50 microliters, and the detection limit was 0.016 mUnits. Isozyme A was heat labile. Upon sialidase treatment, isozymes A, I2 and I1 released sialic acid and were eluted from the column at less acidic pHs. In healthy individuals isozymes A, I2, I1 and B covered about 62.8, 6.9, 15.0 and 15.1% of the total beta-D-N-acetyl-glucosaminidase activity, respectively. During pregnancy the plasma concentration of all isozymes increased. Isozyme I2 showed the highest enhancement (30-fold), followed by I1 (8-fold), B (5.6-fold) and A (3-fold). Interruption of pregnancy by either physiological delivery or ambulatory abortion was followed by a sharp fall of the concentration of all isozymes reaching, in a few days, the control levels.
采用一种自动方法，即在聚缓冲剂交换剂PBE - 94柱上进行层析聚焦、流通式荧光法测定活性以及计算机辅助定量，对健康对照个体和孕妇血浆中的β - D - N - 乙酰氨基葡萄糖苷酶同工酶进行分离和测定。在既定的最佳条件下，该方法将β - D - N - 乙酰氨基葡萄糖苷酶分离为四种同工酶：A、I2、I1和B，分析变异系数分别为1.8%、2.2%、6.4%和4.1%。单次分析时长为25分钟（包括洗脱），同一根柱子可进行10 - 15次连续运行，重现性良好。观察到从1 - 5微升血浆（取决于个体同工酶）到50微升血浆有线性活性响应，检测限为0.016毫单位。同工酶A对热不稳定。经唾液酸酶处理后，同工酶A、I2和I1释放出唾液酸，并在酸性较弱的pH值下从柱上洗脱下来。在健康个体中，同工酶A、I2、I1和B分别占总β - D - N - 乙酰氨基葡萄糖苷酶活性的约62.8%、6.9%、15.0%和15.1%。孕期所有同工酶的血浆浓度均升高。同工酶I2升高幅度最大（30倍），其次是I1（8倍）、B（5.6倍）和A（3倍）。无论是自然分娩还是人工流产终止妊娠后，所有同工酶的浓度均急剧下降，几天内降至对照水平。
