von Krüger W M, Parish J H
Arch Microbiol. 1981 Oct;130(2):150-4. doi: 10.1007/BF00411069.
Several mutants and other variants of Myxococcus xanthus HP100 were obtained with differences in their sensitivity to carbenicillin and other penicillin derivatives. The specific activities of beta-lactamase in different resistant organisms varied from strain to strain but were consistently higher than in HP100. The relative molecular mass (Mr) of the enzyme in M. xanthus HP100 was found to be 22,300. In certain carbenicillin resistant strains a second fraction of beta-lactamase activity of molecular weight 186,000 presumed to be an octamer of the other form was present. The enzyme was found in cell free extracts and also in culture supernatants of all carbenicillin resistant mutants but not in culture supernatants of strain HP100. In all the carbenicillin resistant mutants a part of the intracellular enzyme activity was released by osmotic shock and this activity may be periplasmic. The forms of the enzyme present in the culture supernatants and released by osmotic shock were monomeric. Carbenicillin resistance was not transferable between strains by conjugation. One resistance allele inhibited the transfer of the R factor Sa between myxococci.
获得了几种黄色粘球菌HP100的突变体和其他变体，它们对羧苄青霉素和其他青霉素衍生物的敏感性存在差异。不同抗性菌株中β-内酰胺酶的比活性因菌株而异，但始终高于HP100中的比活性。发现黄色粘球菌HP100中该酶的相对分子质量（Mr）为22,300。在某些羧苄青霉素抗性菌株中，存在分子量为186,000的β-内酰胺酶活性的第二部分，推测为另一种形式的八聚体。该酶存在于无细胞提取物中，也存在于所有羧苄青霉素抗性突变体的培养上清液中，但不存在于菌株HP100的培养上清液中。在所有羧苄青霉素抗性突变体中，一部分细胞内酶活性通过渗透压休克释放，这种活性可能是周质的。培养上清液中存在并通过渗透压休克释放的酶形式为单体。羧苄青霉素抗性不能通过接合在菌株间转移。一个抗性等位基因抑制了R因子Sa在粘球菌之间的转移。
