SEPARATION, PURIFICATION AND PROPERTIES OF BETA-LACTAMASE I AND BETA-LACTAMASE II FROM BACILLUS-CEREUS 569-H-9
SEPARATION, PURIFICATION AND PROPERTIES OF BETA-LACTAMASE I AND BETA-LACTAMASE II FROM BACILLUS-CEREUS 569-H-9
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DOI：
10.1042/bj1430115
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发表时间：
1974-01-01
影响因子：
4.1
通讯作者：
MELLING, J
中科院分区：
文献类型：
--
作者：
DAVIES, RB;ABRAHAM, EP;MELLING, J
1.设计了一种适合于从蜡状芽孢杆菌569/H/9中大规模分离β-内酰胺酶I和β-内酰胺酶II的方法。这两种酶在Celite上吸附后，均以较高的产率洗脱，并经Sephadex CM-50柱层析分离。2.等电聚焦法将β-内酰胺酶I分离为三个主要组分，柱层析分离为两个组分。3.用该方法得到的β-内酰胺酶II的相对分子质量(22000)比β-内酰胺酶I的相对分子质量(28000)低，且只含有一个半胱氨酸残基。4.β-内酰胺酶II不含碳水化合物，但表现出先前分离的蛋白质-碳水化合物复合酶的热稳定性。5.氨基酸分析和胰酶消化‘图谱’表明，β-内酰胺酶I和β-内酰胺酶II之间有一定程度的同源性，但β-内酰胺酶I不是由β-内酰胺酶II的全序列和一个额外的多肽片段组成的。6.6-甲基青霉素和7-甲基头孢菌素对这两种酶的亲和力远低于青霉素和头孢菌素本身。
1. A procedure was devised which is suitable for the isolation of β-lactamase I and β-lactamase II fromBacillus cereus569/H/9 on a large scale. After adsorption on to Celite both enzymes were eluted in good yield and separated by chromatography on Sephadex CM-50. 2. β-Lactamase I was separated into three main components by isoelectric focusing and into two components by chromatography. 3. The Zn2+-requiring β-lactamase II obtained by this procedure had a lower molecular weight (22000) than β-lactamase I (28000) and also differed from the latter in containing one cysteine residue. 4. The β-lactamase II contained no carbohydrate, but showed the thermostability of the enzyme isolated earlier as a protein–carbohydrate complex. 5. Amino acid analyses and tryptic-digest ‘maps’ indicate that some degree of homology between β-lactamase I and β-lactamase II is possible, but that β-lactamase I is not composed of the entire sequence of β-lactamase II together with an additional peptide fragment. 6. A 6-methylpenicillin and a 7-methylcephalosporin showed much lower affinities for both enzymes than did penicillins and cephalosporins themselves.