title: Purification and characterization of a hemocyanin (Hemo1) with potential lignin-modification activities from the wood-feeding termite, Coptotermes formosanus Shiraki.
abstract: Coptotermes formosanus Shiraki is a well-known wood-feeding termite, which can degrade not only cellulose and hemicellulose polysaccharides, but also some aromatic lignin polymers with its enzyme complex to the woody biomass. In this study, a very abundant protein was discovered and purified, using a three-step column chromatography procedure, from the tissue homogenate of the salivary glands and the gut of C. formosanus. Mass spectrometric analysis and the following peptide searching against the mRNA database toward this termite species indicated that the novel protein was a hemocyanin enzyme, termed as Hemo1, which further exhibited a strong oxidase activity in the substrate bioassays toward ABTS [2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)], as well as other aromatic analogues, such as catechol and veratryl alcohols. This oxidative protein was an acid-favored enzyme with a molecular weight at 82 kDa, and highly active at 80 °C. These findings indicated that the novel protein, hemocyanin, discovered from the gut system of C. formosanus, might be an important ligninolytic enzyme involved in the biomass pretreatment processing, which will potentially enhance the digestibility and utilization of biomass polysaccharides in termite digestive systems.
authors.affiliation: Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, 301 Xuefu Rd., Zhenjiang, 212013, Jiangsu, China.
authors.forename: Haifang
authors.initials: H
authors.lastname: Qiu
authors.forename: Alei
authors.initials: A
authors.lastname: Geng
authors.forename: Daochen
authors.initials: D
authors.lastname: Zhu
authors.forename: Yilin
authors.initials: Y
authors.lastname: Le
authors.forename: Jian
authors.initials: J
authors.lastname: Wu
authors.forename: Nienwen
authors.initials: N
authors.lastname: Chow
authors.forename: J H David
authors.initials: JH
authors.lastname: Wu
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Sun
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D052160:Benzothiazoles / Q000737:chemistry; D001592:Benzyl Alcohols / Q000737:chemistry; D002396:Catechols / Q000737:chemistry; D004795:Enzyme Stability; D041981:Gastrointestinal Tract / Q000737:chemistry / Q000201:enzymology; D006433:Hemocyanins / Q000737:chemistry* / Q000302:isolation & purification; D006358:Hot Temperature; D019476:Insect Proteins / Q000737:chemistry* / Q000302:isolation & purification; D020049:Isoptera / Q000737:chemistry* / Q000201:enzymology; D007700:Kinetics; D008031:Lignin / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010088:Oxidoreductases / Q000737:chemistry* / Q000302:isolation & purification; D010449:Peptide Mapping; D012469:Salivary Glands / Q000737:chemistry / Q000201:enzymology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity; D013451:Sulfonic Acids / Q000737:chemistry; D014934:Wood / Q000378:metabolism
chemical_list: D052160:Benzothiazoles; D001592:Benzyl Alcohols; D002396:Catechols; D019476:Insect Proteins; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D008031:Lignin; D006433:Hemocyanins; D010088:Oxidoreductases; C034221:catechol; C042197:veratryl alcohol