Production of Chitooligosaccharides and Their Potential Applications in Medicine

Aam, Berit Bjugan; Heggset, Ellinor B.; Norberg, Anne Line; Sørlie, Morten; Vårum, Kjell M.; Eijsink, Vincent G. H.

doi:10.3390/md8051482

Cited by 527 publications

(368 citation statements)

References 178 publications

(251 reference statements)

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“…The K d values for binding of (GlcNAc) 6 , (GlcNAc) 5 and (GlcNAc) 4 to Chit-42 from T. harzianum determined by Lienemann et al using surface plasmon resonance are approximately 2-, 10-and 5-fold higher than the values reported for ChiB in this study [18]. For ChiB, six subsites, spanning from À3 to + 3 have been described [24] (Fig.…”

Section: Resultscontrasting

confidence: 46%

“…(GlcNAc) 6 binds with a K d of 0.13 ± 0.09 lM (Table 1). The binding is clearly entropically driven (ÀTDS r ¼ À10:9 AE 0:4 kcal=mol and DS r ¼ 37 AE 1 cal=K mol) with an enthalpic penalty (DH r ¼ 1:7 AE 0:3 kcal=mol).…”

Section: Resultsmentioning

confidence: 99%

“…The binding is clearly entropically driven (ÀTDS r ¼ À10:9 AE 0:4 kcal=mol and DS r ¼ 37 AE 1 cal=K mol) with an enthalpic penalty (DH r ¼ 1:7 AE 0:3 kcal=mol). Potential protonation/deprotonation effects coupled to (GlcNAc) 6 binding to ChiB-E144Q were investigated by testing the contribution from buffer ionization to DH r [23]. ITC experiments were carried out as well in HEPES and TRIS, which have different ionization enthalpies compared to potassium phosphate, yielding DH r of 2.0 ± 0.4 kcal/mol and 1.3 ± 0.3 kcal/mol, respectively, indicating no proton transfer upon binding.…”

Section: Resultsmentioning

confidence: 99%

“…1. Thermograms (upper panels) and binding isotherms with theoretical fits (lower panels) obtained for the binding of (GlcNAc) 6 (top left), (GlcNAc) 5 (top right), (GlcNAc) 4 (bottom left), and (GlcNAc) 3 (bottom right) to ChiB-E144Q.…”

Section: Resultsmentioning

confidence: 99%

“…Solutions were thoroughly degassed prior to experiments to avoid air bubbles in the calorimeter. For experiments with (GlcNAc) 6 and (GlcNAc) 5 , typically 15 lM of ChiB-E144Q in 20 mM potassium phosphate buffer (pH 8.0) was placed in the reaction cell with a volume of 1.42 ml, and 500 lM solutions of the ligands in identical buffers as for the protein solutions were placed in the ITC syringe. The concentration of other buffers, HEPES and TRIS at pH 8.0 was also 20 mM.…”

Section: Isothermal Titration Calorimetry Experimentsmentioning

confidence: 99%

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Determination of substrate binding energies in individual subsites of a family 18 chitinase

Norberg¹,

Karlsen²,

Hoell³

et al. 2010

FEBS Letters

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a b s t r a c tThermodynamic parameters for binding of N-acetylglucosamine (GlcNAc) oligomers to a family 18 chitinase, ChiB of Serratia marcescens, have been determined using isothermal titration calorimetry. Binding studies with oligomers of different lengths showed that binding to subsites À2 and +1 is driven by a favorable enthalpy change, while binding to the two other most important subsites, +2 and +3, is driven by entropy with unfavorable enthalpy. These remarkable unfavorable enthalpy changes are most likely due to favorable enzyme-substrate interactions being offset by unfavorable enthalpic effects of the conformational changes that accompany substrate-binding.

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Section: Resultscontrasting

confidence: 46%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Isothermal Titration Calorimetry Experimentsmentioning

confidence: 99%

See 3 more Smart Citations

Determination of substrate binding energies in individual subsites of a family 18 chitinase

Norberg¹,

Karlsen²,

Hoell³

et al. 2010

FEBS Letters

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Cosmeceutical Compounds From Marine Sources

Kim

2012

Kirk-Othmer Encyclopedia of Chemical Technology

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Cosmeceuticals represent a marriage between cosmetics and pharmaceuticals. These cosmeceuticals are cosmetic products with biologically active ingredients purporting to have medical or drug‐like benefits. They are formulated not only to improve the skin's appearance but also to enhance positive physiological effects at the cellular level. Because of the demand of consumers, cosmeceutical products have become one of the fastest growing industries. Simultaneously, it is necessary to discover novel bioactive substances with efficient, safe, and stable properties from natural sources for cosmeceutical development. Recently, marine resources have been demonstrated as rich sources of structurally diverse biologically active compounds with great cosmeceutical potential. Numerous compounds isolated from marine organisms exhibit various cosmeceutical activities such as antioxidant, antiinflammation, antiallergy, antiaging and antiwrinkling effect, tyrosinase and MMP inhibition, and ultraviolet protection. Accordingly, this contribution focuses on cosmeceutical compounds derived from marine sources and presents a brief overview of their cosmeceutical activities with health benefits.

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Chitin: A Structural Biopolysaccharide with Multiple Applications

Martinez

Falomir

Gozalbo

2014

Encyclopedia of Life Sciences

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Chitin is a naturally occurring fibre‐forming polymer that plays a protective role in many lower eukaryotes similar to that of cellulose in plants. Chemically it is a long‐chain unbranched polysaccharide made of N ‐acetylglucosamine residues linked through β‐1,4 covalent bonds; it is the second most abundant organic compound in nature, after cellulose. Taking into account the role played by chitin in different biological structures (i.e. fungal cell walls, insect peritrophic matrix, insect and crustacean cuticles, eggshells from nematodes, cyst wall of protozoa), its metabolism (biosynthesis and degradation) is essential for different morphogenetic events. Absent in vertebrates and plants, chitin participates in host–parasite interactions and represents a parasite‐specific target for chemotherapeutic attack and also plays a role in host immune responses. Because of its abundance in nature and its properties, biotechnological applications of chitin derivatives, such as chitosan and chito‐oligosaccharides, are currently an expanding area in biomedicine, pharmaceutical and food technology and agro‐biosciences. Key Concepts: Chitin is a long‐chain unbranched polysaccharide made of β‐1,4‐linked anhydro‐2‐acetamido‐2‐deoxy‐ d ‐glucose (GlcNAc) which forms crystalline fibrillar structures following association of adjacent chains through hydrogen bonds between the N–H and the CO groups. Nascent chitin is a growing chitin chain which is being synthesised by the chitin synthase and it represents a good substrate for chitinolytic enzymes. Microfibrillar chitin is a crystalline structure formed by chains of the polysaccharide which associate through hydrogen bonds between adjacent chains and it is responsible for the physico‐chemical properties of the polymer. The fungal cell wall is a supramolecular network outside the plasma membrane, formed by structural polysaccharides, including chitin, and proteins and glycoproteins, that protects the fungal cell and determines morphology, similarly to cuticle (exosqueleton) in insects. Insect cuticle (exosqueleton) is an extracellular matrix covering the epidermis and trachea, composed mainly by chitin (and proteins), which protects the animal and confers morphology. The peritrophic membrane (matrix) is an extracellular layer that covers the midgut in most arthropods and it is made of chitin, proteins and proteoglycans, and provides protection to the underlaying digestive cells. Chitin biosynthesis is a strongly regulated process, both spatially and temporally, as chitin deposition is essential for fungal growth and development (moulting) in arthropods. Chitin synthases are membrane bound enzymes that incorporate the substrate (UDP‐ N ‐acetylglucosamine) from the cytosol to the nascent chitin chain that is extruded outside the membrane. Chitinases are chitin‐hydrolysing enzymes that play important roles in the physiology of chitin‐containing eukaryotes, and chitinolytic bacteria are active in a scavenging role by degrading massive amounts of chitin in marine and soil biomass, avoiding its accumulation and favouring the utilisation of chitin as a renewable source. The absence of chitin in vertebrates and plants makes the chitin metabolism a potentially useful parasite‐specific target for chemotherapeutic attack. In mammals, chitin regulates immune responses playing a role in inflammation, and allergic diseases. In plants, chitin elicits defence responses, and in leguminous plants, chitin oligosaccharides produced by rhizobia promote plant nodulation. Owing to their abundance in nature and properties, chitin, chitosan and their derivatives have gained potential interest for a wide range of areas, including biopharmaceutical and biomedical applications.

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Production of Chitooligosaccharides and Their Potential Applications in Medicine

Cited by 527 publications

References 178 publications

Determination of substrate binding energies in individual subsites of a family 18 chitinase

Determination of substrate binding energies in individual subsites of a family 18 chitinase

Cosmeceutical Compounds From Marine Sources

Chitin: A Structural Biopolysaccharide with Multiple Applications

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