A PROTEOLYTIC ENZYME PRODUCED BY GROUP A STREPTOCOCCI WITH SPECIAL REFERENCE TO ITS EFFECT ON THE TYPE-SPECIFIC M ANTIGEN.
A PROTEOLYTIC ENZYME PRODUCED BY GROUP A STREPTOCOCCI WITH SPECIAL REFERENCE TO ITS EFFECT ON THE TYPE-SPECIFIC M ANTIGEN.
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DOI：
10.1084/jem.81.6.573
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发表时间：
1945-06-01
期刊：
影响因子：
--
通讯作者：
Elliott SD
中科院分区：
文献类型：
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作者：
Elliott SD
1. A组链球菌有时在肉汤培养中产生胞外蛋白水解酶。2.在合适的培养条件下，该酶已在大多数Griffith类型的代表性培养物中得到证实。通过小鼠连续传代可以抑制给定菌株的产生，并且已经发现如此产生的变体在人工培养基中的传代培养中保持这种特征变化。3.在某些条件下，该酶攻击迄今为止测试的所有A组链球菌的型特异性M抗原，除了28型。该酶在37°C时表现出最大活性：在此温度下生长的产酶培养物所制备的提取物缺乏M抗原;有时可通过在22° C下培养链球菌诱导产酶菌株在提取物中产生M物质。当在37° C下生长时，提取物中产生M物质，不产生酶。4.人和兔纤维蛋白被攻击，链球菌纤维蛋白溶解酶也被该酶灭活。其他敏感底物包括酪蛋白、牛奶、明胶和苯甲酰基-l-氨基乙酰胺，但不包括l-亮氨酰甘氨酰甘氨酸。5.该酶的一般性质类似于木瓜蛋白酶和一些组织蛋白酶的性质：在活细菌存在下在肉汤培养物中产生的还原条件下具有活性;它也被将二硫化物还原为巯基的物质激活，例如氰化钾，半胱氨酸，谷胱甘肽和巯基乙酸，但它不被抗坏血酸激活。该酶可被碘乙酸灭活，也可被正常兔或小鼠血清灭活。
1. Group A streptococci sometimes produce in broth culture an extracellular proteolytic enzyme. 2. Under suitable cultural conditions the enzyme has been demonstrated in representative cultures of most of the Griffith types. Its production by a given strain may be suppressed by serial passage through mice and the variant so produced has been found to maintain this change in character on subculture in artificial media. 3. Under certain conditions, the enzyme attacks the type-specific M antigens of all the group A streptococci so far tested, with the exception of that of type 28. The enzyme exhibits its maximal activity at 37°C.: Extracts made from enzyme-producing cultures which have been grown at this temperature lack the M antigen; enzyme-producing strains may sometimes be induced to yield M substance in extracts by culturing the streptococci at 22° C. Cultures which, when grown at 37° C. yield M substance in extracts, do not produce the enzyme. 4. Human and rabbit fibrin are attacked and streptococcal fibrinolysin is also inactivated by the enzyme. Other susceptible substrates include casein, milk, gelatin, and benzoyl-l-arginineamide but not l-leucylglycylglycine. 5. The general properties of the enzyme resemble those of papain and some of the cathepsins: It is active under the reducing conditions produced in broth cultures by the presence of living bacteria; it is also activated by substances which reduce disulfide to sulfhydryl groups, e.g. potassium cyanide, cysteine, glutathione, and thioglycollic acid, but it is not activated by ascorbic acid. The enzyme is inactivated by iodoacetic acid and also by normal rabbit or mouse serum.