Chitin binding protein (CBP21) in the culture supernatant of Serratia marcescens 2170
Chitin binding protein (CBP21) in the culture supernatant of Serratia marcescens 2170
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DOI：
10.1271/bbb.62.128
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发表时间：
1998-01-01
影响因子：
1.6
通讯作者：
Watanabe, T
中科院分区：
文献类型：
--
作者：
Suzuki, K;Suzuki, M;Watanabe, T
几丁质结合蛋白（CBP 21）是粘质沙雷氏菌（Serratiamarcescens）2170培养上清中的主要蛋白质，分子量为21 kDa。cbp基因编码197个氨基酸的多肽，计算大小为21.6 kDa，含有27个氨基酸的推定信号序列。氨基酸序列分析表明，CBP 21与橄榄绿链霉菌CHB 1的氨基酸序列相似性为45.3%。纯化的CBP 21制备的大肠杆菌携带克隆的cbp基因的周质部分显示其最高的结合活性鱿鱼甲壳素（β-甲壳素），其次是胶体甲壳素和再生甲壳素。pH值对CBP 21与再生几丁质的结合活性有影响，特别是低pH值会显著降低结合活性。在远亲微生物链霉菌属和沙雷氏菌属中存在类似的几丁质结合蛋白，表明这种类型的几丁质结合蛋白在几丁质分解微生物中广泛分布。
A chitin binding protein (CBP21) 21kDa in size, is a major protein in the culture snpernatant when Serratia marcescens 2170 is grown in the presence of chitin, The gene (cbp) for CBP21 was found to be located in a region 1.5 kb downstream of the chiB gene encoding chitinase B. The cbp gene encodes a polypeptide of 197 amino-acids with a calculated size of 21.6 kDa containing a putative signal sequence of 27 amino acids. Comparison of the amino acid sequence of the deduced polypeptide with that of other proteins showed that CBP21 is similar (45.3% amino acid identity) to CHB1 of Streptomyces olivaceoviridis. Purified CBP21 prepared from the periplasmic fraction of Escherichia coli carrying the cloned cbp gene showed its highest binding activity to squid chitin (beta-chitin) followed by colloidal chitin and regenerated chitin. Binding of CBP21 to regenerated chitin was affected by pH, in particular, low pH reduced binding activity markedly. The presence of similar chitin binding proteins in the distantly related microorganisms, Streptomyces and Serratia, suggests a wide distribution of this type of chitin binding protein in chitinolytic microorganisms.