Selective N-acylation of chitosan

Hirano, Seishiro; Ohe, Yasuo; Ono, Haruhiro

doi:10.1016/s0008-6215(00)84198-1

Cited by 261 publications

(96 citation statements)

References 8 publications

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“…Glycol chitin for the chitinase assay was prepared by the method of Yamada and Imoto (36). Regenerated chitin was prepared from chitosan by the method of Hirano et al (9). cc-35S-dATP was purchased from Amersham Corp.…”

Section: Methodsmentioning

confidence: 99%

Structure of the gene encoding chitinase D of Bacillus circulans WL-12 and possible homology of the enzyme to other prokaryotic chitinases and class III plant chitinases

et al. 1992

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The gene (chiD) encoding the precursor of chitinase D was found to be located immediately upstream of the chiA gene, encoding chitinase Al, which is a key enzyme in the chitinase system of Bacillus circulans WL-12. Sequencing analysis revealed that the deduced polypeptide encoded by the chiD gene was 488 amino acids long and the distance between the coding regions of the chiA and chiD genes was 103 bp. Remarkable similarity was observed between the N-terminal one-third of chitinase D and the C-terminal one-third of chitinase Al. The N-terminal 47-amino-acid segment (named ND) of chitinase D showed a 61.7% amino acid match with the C-terminal segment (CA) of chitinase Al. The following 95-amino-acid segment (R-D) of chitinase D showed 62.8 and 60.6% amino acid matches, respectively, to the previously reported type III-like repeating units R-1 and R-2 in chitinase Al, which were shown to be homologous to the fibronectin type III sequence. A 73-amino-acid segment (residues 247 to 319) located in the putative activity domain of chitinase D was found to show considerable sequence similarity not only to other bacterial chitinases and class III higher-plant chitinases but also to Streptomyces plicatus endo-o-N-acetylglucosaminidase H and the Kluyveromyces lactis killer toxin a subunit. The evolutionary and functional meanings of these similarities are discussed.Chitinases are commonly found in a wide range of organisms including bacteria (3, 26, 32), fungi (5, 23), higher plants (2, 24), insects (7, 14), crustaceans (17), and some vertebrates (4). The roles of these chitinases could be divided into several categories. For example, a major role of chitinases found in fungi, crustaceans, and insects is modification of the organism's structural constituent chitin. The production of chitinases by plants is considered to be a part of their defense mechanism against fungal pathogens, which contain chitin as a structural constituent. Bacteria produce chitinase to digest chitin primarily to utilize it as a carbon and energy source. Higher-plant chitinases can be divided into at lease three classes, class I, class II, and class III based on amino acid sequence features (29).Bacillus circulans WL-12 is one of the bacteria which excrete chitinases into culture medium (32). As a first attempt to elucidate the mechanism of chitin degradation by bacteria and the evolution of chitinase genes, we have recently cloned and sequenced the chiA gene, which encodes chitinase Al, the key enzyme in the B. circulans chitinase system, and compared the sequence with those of some other proteins (33). The N-terminal two-thirds of the deduced amino acid sequence of chitinase Al showed a 33% amino acid match to chitinase A of Serratia marcescens (12). In addition, the R-1 and R-2 segments, which are 95-aminoacid tandem repeats in chitinase Al, have been found to be homologous to the so-called type III repeats of firbronectin.

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Section: Methodsmentioning

confidence: 99%

Structure of the gene encoding chitinase D of Bacillus circulans WL-12 and possible homology of the enzyme to other prokaryotic chitinases and class III plant chitinases

et al. 1992

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“…Regenerated chitin for chitinase adsorption was prepared from chitosan by the method of Molano et al (10). This method is a modification of the method of Hirano et al (5). Oligomers of GlcNAc were obtained from Seikagaku Kogyo Co., Ltd. (Tokyo, Japan).…”

Section: Methodsmentioning

confidence: 99%

Chitinase system of Bacillus circulans WL-12 and importance of chitinase A1 in chitin degradation

et al. 1990

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Bacillus circulans WL-12, isolated as a yeast cell wall-lytic bacterium, secretes a variety of polysaccharidedegrading enzymes into culture medium. When chitinases of the bacterium were induced with chitin, six distinct chitinase molecules were detected in the culture supernatant. These chitinases (Al, A2, Bi, B2, C, and D) showed the following distinct sizes and isoelectric points: Mr 74,000, pl 4.7 (Al); Mr 69,000, pl 4.5 (A2); Mr 38,000, pl 6.6 (Bi); Mr 38,000, pl 5.9 (B2); Mr 39,000, pl 8.5 (C); and Mr 52,000, pl 5.2 (D). Among these chitinases, Al and A2 had the highest colloidal-chitin-hydrolyzing activities. Chitinase Al showed a strong affinity to insoluble substrate chitin. Purified chitinase Al released predominantly chitobiose [(GlcNAc)2] and a trace amount of N-acetylglucosamine (GlcNAc) from colloidal chitin. N-terminal amino acid sequence analysis of chitinases Al and A2 indicated that chitinase A2 was generated from chitinase Al, presumably by proteolytic removal of a C-terminal portion of chitinase Al. Since chitinase A2 did not have the ability to bind to chitin, the importance of the C-terminal region of chitinase Al to the strong affinity of chitinase Al to substrate chitin was suggested. Strong affinity of the chitinase seemed to be required for complete degradation of insoluble substrate chitin. From these results, it was concluded that chitinase Al is the key enzyme in the chitinase system of this bacterium.Chitin, an insoluble linear P-1,4-linked polymer of Nacetylglucosamine (GlcNAc), is one of the most abundant polysaccharides in nature. It is a common constituent of insect exoskeletons, shells of crustaceans, and fungal cell walls. These organisms containing constituent chitin produce chitinases (EC 3.2

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“…In detail, reacetylated chitosan was prepared from horseshoe crab chitosan (Sigma) as previously described (18). Various amounts of reacetylated chitosan suspended in TBS were dispensed into preweighed tubes and pelleted (30 s, 10,000 ϫ g), and all liquid was removed.…”

Section: /Ebi Data Bank With Accession Number(s) Af327453 and Af327454mentioning

confidence: 99%

A Novel Family of Chitin-binding Proteins from Insect Type 2 Peritrophic Matrix

Wijffels¹,

Eisemann²,

Riding³

et al. 2001

Journal of Biological Chemistry

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The peritrophic matrix is a prominent feature of the digestive tract of most insects, but its function, formation, and even its composition remain contentious. This matrix is a molecular sieve whose toughness and elasticity are generated by glycoproteins, proteoglycans, and chitin fibrils. We now describe a small, highly conserved protein, peritrophin-15, which is an abundant component of the larval peritrophic matrices of the Old World screwworm fly, Chrysomya bezziana, and sheep blowfly, Lucilia cuprina. Their deduced amino acid sequences code for a 8-kDa secreted protein characterized by a highly conserved and novel register of six cysteines. Two Drosophila homologues have also been identified from unannotated genomic sequences. Recombinant peritrophin-15 binds strongly and specifically to chitin; however, the stoichiometry of binding is low (1:10,000 N-acetyl glucosamine). We propose that peritrophin-15 caps the ends of the chitin polymer. Immunogold studies localized peritrophin-15 to the peritrophic matrix and specific vesicles in cells of the cardia, the small organ of the foregut responsible for peritrophic matrix synthesis. The vesicular contents are disgorged at the base of microvilli underlying the newly formed peritrophic matrix. This is the first time that the process of synthesis and integration of a peritrophic matrix protein into the nascent peritrophic matrix has been observed.

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Selective N-acylation of chitosan

Cited by 261 publications

References 8 publications

Structure of the gene encoding chitinase D of Bacillus circulans WL-12 and possible homology of the enzyme to other prokaryotic chitinases and class III plant chitinases

Structure of the gene encoding chitinase D of Bacillus circulans WL-12 and possible homology of the enzyme to other prokaryotic chitinases and class III plant chitinases

Chitinase system of Bacillus circulans WL-12 and importance of chitinase A1 in chitin degradation

A Novel Family of Chitin-binding Proteins from Insect Type 2 Peritrophic Matrix

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