On chemistry of γ-chitin

Kaya, Murat; Mujtaba, Muhammad; Ehrlich, Hermann; Salaberria, Asier M.; Baran, Talat; Amemiya, Chris T.; Galli, Roberta; Akyüz, Lalehan; Sargın, İdris; Labidi, Jalel

doi:10.1016/j.carbpol.2017.08.076

Cited by 259 publications

(204 citation statements)

References 56 publications

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“…On the other hand, several studies including ours could not detect chitin deacetylase activity in vitro from comparable preparations (8,27,28). Nevertheless, the finding that naturally occurring chitin isolated from insects does indeed have up to about 20% deacetylated sugars (glucosamine residues) (29) indicates that deacetylation must occur in vivo. It is likely that in insect cuticle, deacetylation occurs on nascent chitin chains and that in vitro studies failed to reproduce those conditions/substrates/presence of co-factors required for activity.…”

Section: Discussionmentioning

confidence: 54%

Group I chitin deacetylases are essential for higher order organization of chitin fibers in beetle cuticle

Noh

Muthukrishnan

Kramer

et al. 2018

Journal of Biological Chemistry

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Roles in the organization of the cuticle (exoskeleton) of two chitin deacetylases (CDAs) belonging to group I, and, as well as two alternatively spliced forms of the latter, and, from the red flour beetle, , were examined in different body parts using transmission EM and RNAi. Even though all are co-expressed in cuticle-forming cells from the hardened forewing (elytron) and ventral abdomen, as well as in the softer hindwing and dorsal abdomen, there are significant differences in the tissue specificity of expression of the alternatively spliced transcripts. Loss of either TcCDA1 or TcCDA2 protein by RNAi causes abnormalities in organization of chitinous horizontal laminae and vertical pore canals in all regions of the procuticle of both the hard and soft cuticles. Simultaneous RNAi for and produces the most serious abnormalities. RNAi of either or affects cuticle integrity to some extent. Following RNAi, there is accumulation of smaller disorganized fibers in both the horizontal laminae and pore canals, indicating that TcCDAs play a critical role in elongation/organization of smaller nanofibers into longer fibers, which is essential for structural integrity of both hard/thick and soft/thin cuticles. Immunolocalization of TcCDA1 and TcCDA2 proteins and effects of RNAi on their accumulation indicate that these two proteins function in concert exclusively in the assembly zone in a step involving the higher order organization of the procuticle.

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Section: Discussionmentioning

confidence: 54%

Group I chitin deacetylases are essential for higher order organization of chitin fibers in beetle cuticle

Noh

Muthukrishnan

Kramer

et al. 2018

Journal of Biological Chemistry

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“…As the main component of defense armor in most insects and crustaceans, chitin has a high fracture toughness that is comparable to natural materials such as bone 5b,39. Chitin can be found in three polymorphic forms: α, β, and γ . The basic unit of these crystals is β‐1,4‐ N ‐acetyl‐ d ‐glucosamine (GlcNAc) ((C 8 H 13 O 5 N)n) 38b.…”

Section: Atomic Scalementioning

confidence: 99%

Multiscale Toughening Mechanisms in Biological Materials and Bioinspired Designs

et al. 2019

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Biological materials found in Nature such as nacre and bone are well recognized as light-weight, strong, and tough structural materials. The remarkable toughness and damage tolerance of such biological materials are conferred through hierarchical assembly of their multiscale (i.e., atomicto macroscale) architectures and components. Herein, the toughening mechanisms of different organisms at multilength scales are identified and summarized: macromolecular deformation, chemical bond breakage, and biomineral crystal imperfections at the atomic scale; biopolymer fibril reconfiguration/deformation and biomineral nanoparticle/nanoplatelet/ nanorod translation, and crack reorientation at the nanoscale; crack deflection and twisting by characteristic features such as tubules and lamellae at the microscale; and structure and morphology optimization at the macroscale. In addition, the actual loading conditions of the natural organisms are different, leading to energy dissipation occurring at different time scales. These toughening mechanisms are further illustrated by comparing the experimental results with computational modeling. Modeling methods at different length and time scales are reviewed. Examples of biomimetic designs that realize the multiscale toughening mechanisms in engineering materials are introduced. Indeed, there is still plenty of room mimicking the strong and tough biological designs at the multilength and time scale in Nature.

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“…S2). Chitin exists in three main allomorphic forms (a-, b-, g-) [5] and by comparing the AoL spectrum to those of known aand b-chitin controls, we observe a pattern most closely resembling that of b-chitin. This is consistent with the fact that bchitin is usually associated with softer, more pliable structures than a-chitin [5].…”

Section: Resultsmentioning

confidence: 84%

“…Chitin exists in three main allomorphic forms (a-, b-, g-) [5] and by comparing the AoL spectrum to those of known aand b-chitin controls, we observe a pattern most closely resembling that of b-chitin. This is consistent with the fact that bchitin is usually associated with softer, more pliable structures than a-chitin [5]. Lastly, we used two unrelated histochemical probes to detect chitin in whole-mount and histological preparations of multiple chondrichthyan species, including the spotted ratfish, Hydrolagus colliei ( Fig.…”

Section: Resultsmentioning

confidence: 84%

Evidence of Chitin in the Ampullae of Lorenzini of Chondrichthyan Fishes

Phillips

Tang

Hassan³

et al. 2019

Preprint

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Chitin is produced by a variety of organisms using enzymes called chitin synthases and was recently discovered in certain vertebrates. In our ongoing investigations into the presence of vertebrate chitin, we unexpectedly found it within the electrosensory organs, known as Ampullae of Lorenzini, of diverse cartilaginous fishes. We used histochemical reagents, chemical analyses, and enzymatic digestions to confirm our findings. Further, in situ hybridization with a sequence from the little skate (Leucoraja erinacea) revealed that chitin synthase expression is localized to cells inside the organs. These findings indicate that cartilaginous fishes endogenously synthesize chitin and beg further investigation into the function of chitin in the electrosensory system.

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On chemistry of γ-chitin

Cited by 259 publications

References 56 publications

Group I chitin deacetylases are essential for higher order organization of chitin fibers in beetle cuticle

Group I chitin deacetylases are essential for higher order organization of chitin fibers in beetle cuticle

Multiscale Toughening Mechanisms in Biological Materials and Bioinspired Designs

Evidence of Chitin in the Ampullae of Lorenzini of Chondrichthyan Fishes

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