p1. The β-lactamases specified by iKlebsiella aerogenes/i 418 and the R-factor R-7268 have been partially purified. 2. The molecular weights of the iK. aerogenes/i strains 418 and 373, iAerobacter cloacae/i 53, R-7268 and R-TEM β-lactamases were all about 20000; that of the enzymes from iEscherichia coli/i strains 419 and 214T was about 31000. 3. These enzymes were also compared by means of their iKsubm/sub/i values for benzylpenicillin and ampicillin, and their behaviour on starch-gel electrophoresis. 4. The β-lactamases specified by the two iKlebsiella/i strains, the iAerobacter/i strain, and the R-factors R-TEM and R-7268 were found to comprise a broadly similar group. However, within this group, only two enzymes seemed to be identical, namely those specified by the two R-factors. The two iE. coli/i strains produce identical β-lactamases which are very different from the ‘iKlebsiella/i/iAerobacter/i-type’ enzymes./p
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机译：> 1。由产气克雷伯氏菌418和R因子R-7268指定的β-内酰胺酶已被部分纯化。 2. K的分子量。产气杆菌418和373菌株，阴沟杆菌53，R-7268和R-TEMβ-内酰胺酶均约为20000。大肠埃希氏大肠杆菌419和214T菌株的酶值约为31000。3.还通过它们的 K m 值比较了这些酶。苄青霉素和氨苄青霉素的合成及其在淀粉凝胶电泳中的行为。 4.发现由两个克雷伯氏菌菌株，气杆菌属菌株和R因子R-TEM和R-7268所指定的β-内酰胺酶具有广泛相似的特征。组。然而，在这一组中，似乎只有两种酶是相同的，即由两个R因子指定的那些。两个 E。大肠杆菌菌株产生相同的β-内酰胺酶，与“克雷伯氏菌” /“气杆菌型”酶大不相同。
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