抗体与酶都是高分子物质，在进化过程中形成各自不同的使命。它们的结构虽然不同，但却具有两大共性：都是蛋白质，都能高选择性高紧密性地与靶分子结合，抗体特异性地结合抗原且帮助巨噬细胞摄入，并摧毁抗原，酶则高选择性地结合化学反应中特定结构的物质，并催化化学反应，使反应在温和条件下高效率地进行。
但酶的种类与抗体的种类相比简直不可同日而语，已知的酶仅有几千种，而抗体种类千万种之多，从原则上讲，免疫系统能对任何抗原产生抗体，因而抗体的种类是无穷尽的。如果能赋予抗体以酶的催化活性，则无疑可使酶的王国极大地扩展，使温和条件下高选择性高效率的化学反应极大地增加，其前途和效应都是不可估量的。
使抗体兼具有酶的性质，其难度也是可想而知的，它激励着科学家们孜孜以求、不懈努力地去探索。
抗体酶通常采用诱导的方法，即单克隆技术来制备。因为过渡态极不稳定，是一种稍纵即逝的结构，其寿命约为10-13秒，因此不可能用它对动物进行免疫。用1个或几个其它原子或原子团取代过渡态的特定原子或原子团获得在形状、电性、酸碱性等诸方面与过渡态相似的稳定物质，即过渡态相似物，然后用它作为半抗原和载体蛋白一起对动物进行免疫，最后取免疫动物的脾细胞与骨髓肿瘤细胞进行杂交，其杂交细胞就会源源不断地分泌单克隆抗体，经筛选和纯化，可得抗体酶。
抗体酶亦可用拷贝的方法获得。用有已知酶的动物作为抗原动物，抗原通过单克隆技术，制得抗该种酶的抗体。再以此种抗体免疫动物，再次采用单克隆技术，经筛选与纯化，就可获得具有原来酶活性的抗体酶。因为抗原与该抗原产生的抗体具有互补性，经过上述两次拷贝，就把酶的活性部位的信息翻录到抗体酶上，使该抗体酶能高选择性地催化原酶所催化的反应。这种方法虽然不能产生新的催化反应，但对自然界来源稀少的紧缺酶，不失为一种有价值的有潜力的方法。
抗体酶的另一来源为天然抗体酶。近来，已在患全身红斑狼疮病的病人血清中分离出抗体酶，它具有催化水解DNA的活性。这提示人们：在有免疫性缺陷的病人体内存在着抗体酶。
此外，通过基因工程、蛋白质工程和化学修饰等方法亦可制得抗体酶。将编码的人工合成的基因转入细菌或酵母的表达系统，采用突变手段随机产生抗体，经筛选和纯化可得抗体酶；或对抗体进行化学修饰，引入
A. 抗体与酶的区别
B. 酶的种类
C. 抗体酶的产生
D. 抗体酶的研究
| For laymen ethnology is probably the
most interesting of the biological sciences for the very reason that it concerns
animals in their normal activities and therefore, if we wish, we can assess the
possible dangers and advantages in our own behavioral roots. Ethnology also is
interesting methodologically because it combines in new ways very scrupulous
field observations with experimentation in laboratories. The field workers have had some handicaps in winning respect for themselves. For a long time they were considered as little better than amateur animal-watchers certainly not scientists, since their facts were not gained by experimental procedures: they could not conform to the hard-and-fast rule that a problem set up and solved by one scientist must be tested by other scientists, under identical conditions and reaching identi A. are difficult and quick to follow B. must be carried out in a strict and quick way C. must be followed strictly to avoid false and loose results D. hard and unreasonable for scientists to observe [单选题] 检查与考核内容包括(一)检修质量。(二)检修计划和方案。(三)()(四)抢修管理。(五)新技术、新工艺、新装备推广应用情况。
A.精益化作业 B.安全作业 C.施工作业 D.标准化作业 [多选题]3.611.第611题
设备的缺陷按其严重程度可分为()。 A.一般缺陷 B.重大缺陷 C.紧急缺陷 D.特殊缺陷 [单选题]某设备的账面原价为50000元，预计使用年限为4年，预计净残值率为4%，采用双倍余额递减法计提折旧，该设备在第1年应计提的折旧额为( )元
A.22000 B.25000 C.23000 D.24000 [填空题]At every stage of development, clothes can help establish a person’’s identity for himself and for those with whom he interacts. The childhood game of "dressing up" in parents’’ 1 provides the opportunity for the child to 2 the roles he will be 3 to play in adult life.
The degree 4 which a person chooses clothes that 5 the roles will affect his performance in those roles. Clothes are an important factor in developing 6 of self-confidence and self-respect, 7 when you look good, you feel good. For most people, clothes are often a source of 8 reaction from others, since in our culture we are more 9 to compliment a person on his 10 than on other 11 of the "self"
Most Americans also 12 that a proper appearance and proper dress are the keys 13 association with the right crowd, which 14 opens the doors to job advancement, increased income, and greater prestige.
Our clothing needs are 15 by a multitude of circumstances, because buying motives are 16 sim
A. A．things B． aspects C．parts D． points [判断题]选用主电路开关电器，首先是要保证满足电路功能要求，即负载要求，同时也要做到所选开关电器在技术.经济指标等各方面合理，在能满足所担负的配电控制.控制和保护任务的前提下，能充分发挥本身所具备的各种功能和作用。( )
A.正确 B.错误 [判断题]原用于表示农药浓度的ppm目前在国际上已不再使用，现在可用mg/kg表示。
[单选题]患者身份识别原则正确的是( )
A.进行高危护理活动时,应当主动使用两种以上的身份识别方式 B.身份识别的内容仅包括姓名和诊断 C.急救过程中,无法辨认患者身份时,应核实身份后再进行操作 D.实习护士可以协助带教护士进行身份核对 E.患者籍贯不是身份核对内容之一 [单项选择]将目之不同部位分属于五脏之说，源于
A. 《重订通俗伤寒论》 B. 《灵枢·大惑论》 C. 《渚病源候论》 D. 《四诊抉微》 E. 《龙树眼论》 我来回答: 提交
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