人血红细胞蛋白质酪氨酸磷酸酶（PTPP）的研究──Ⅲ．胞浆PTPP与红细胞膜的结合及其结合后的主要性质

用部分纯化的胞浆ＰＴＰＰ分别与去ＰＴＰＰ活性的红细胞血影（ｄＰＴＰＰ－Ｇｈｏｓｔ）和内向外翻红细胞膜（ｄＰＴＰＰ－ＩＯＶ）结合，结果发现：胞浆ＰＴＰＰ不仅能与红细胞膜结合，而且与ｄＰＴＰＰ－ＩＯＶ的结合能力强于与ｄＰＴＰＰ－Ｇｈｏｓｔ的结合。很多因素，诸如：温度，ｐＨ，离子强度，结合时间及某些试剂等不仅对ＰＴＰＰ与膜的结合有影响，且对ＰＴＰＰ与ｄＰＴＰＰ－１０Ｖ结合的影响比与ｄＰＴＰＰ－Ｇｈｏｓｔ结合的影响更为显著。当胞浆ＰＴＰＰ与红细胞膜结合后，其性质发生变化，这主要表现在稳定性增强；Ｋｍ减小；Ｚｎ￣（２＋）、ＶＯ等的抑制作用及ＥＤＴＡ、甘油等的激活作用都明显减弱，甚至向相反的作用转化。此外，红细胞膜的磷酸化／脱磷酸化对ＰＴＰＰ的结合有影响，这暗示磷醚化作用对此可能具有调节意义。

Research for Phosphotyrosyl Protein Phosphatase (PTPP) of Human Erythrocytes Ⅲ. Association of Cytosolic PTPP Asssociated with Membrane and Properties of PTPP Associated with Membrane

Using partially purified cytosolic PTPP to combine with dPTPP-ghost and dPTPP-IOV membrane of human erythrocytes, respectively, we obtained these results: not only the cytosolic PTPP could associate with membrane, but the ability with dPTPP-IOV membrane was greater than that of PTPP doing with dPTPP-ghost. Many factors such as temperature, pH, ionic strength,association time and some reagents etc. could influence the association,and the effects on the association of PTPP with dPTPP-IOV membrane were more apparent than that of it with dPTPP-ghost. The properties of PTPP associated with membrane (dPTPP-IOV) were different from cytosolic dissociating PTPP. For example, the heat-stability was increased; the Km was decreased; and the inhibition of Zn￣(2+),VO and activtion of EDTA, glycerol etc. were apparently weakened. Besides, by treating the dPTPP-IOV membrane with PTPP, PTK, CIP etc. respectively, we found that its association abilitys with cytosolic PTPP was weakened. This indicates that phosphorylation / dephosphorylation may control the association of PTPP with membrane.