scholarly journals Structure of the Arabidopsis Glucan Phosphatase LIKE SEX FOUR2 Reveals a Unique Mechanism for Starch Dephosphorylation

2013 ◽  
Vol 25 (6) ◽  
pp. 2302-2314 ◽  
Author(s):  
D. A. Meekins ◽  
H.-F. Guo ◽  
S. Husodo ◽  
B. C. Paasch ◽  
T. M. Bridges ◽  
...  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qingqiao Xie ◽  
Yuandi Zhuang ◽  
Gaojun Ye ◽  
Tiankuo Wang ◽  
Yi Cao ◽  
...  

AbstractMany soft tissues are compression-stiffening and extension-softening in response to axial strains, but common hydrogels are either inert (for ideal chains) or tissue-opposite (for semiflexible polymers). Herein, we report a class of astral hydrogels that are structurally distinct from tissues but mechanically tissue-like. Specifically, hierarchical self-assembly of amphiphilic gemini molecules produces radial asters with a common core and divergently growing, semiflexible ribbons; adjacent asters moderately interpenetrate each other via interlacement of their peripheral ribbons to form a gel network. Resembling tissues, the astral gels stiffen in compression and soften in extension with all the experimental data across different gel compositions collapsing onto a single master curve. We put forward a minimal model to reproduce the master curve quantitatively, underlying the determinant role of aster-aster interpenetration. Compression significantly expands the interpenetration region, during which the number of effective crosslinks is increased and the network strengthened, while extension does the opposite. Looking forward, we expect this unique mechanism of interpenetration to provide a fresh perspective for designing and constructing mechanically tissue-like materials.


2019 ◽  
Vol 9 ◽  
pp. 204512531988191 ◽  
Author(s):  
Cathy Davies ◽  
Sagnik Bhattacharyya

Psychotic disorders such as schizophrenia are heterogeneous and often debilitating conditions that contribute substantially to the global burden of disease. The introduction of dopamine D2 receptor antagonists in the 1950s revolutionised the treatment of psychotic disorders and they remain the mainstay of our treatment arsenal for psychosis. However, traditional antipsychotics are associated with a number of side effects and a significant proportion of patients do not achieve an adequate remission of symptoms. There is therefore a need for novel interventions, particularly those with a non-D2 antagonist mechanism of action. Cannabidiol (CBD), a non-intoxicating constituent of the cannabis plant, has emerged as a potential novel class of antipsychotic with a unique mechanism of action. In this review, we set out the prospects of CBD as a potential novel treatment for psychotic disorders. We first review the evidence from the perspective of preclinical work and human experimental and neuroimaging studies. We then synthesise the current evidence regarding the clinical efficacy of CBD in terms of positive, negative and cognitive symptoms, safety and tolerability, and potential mechanisms by which CBD may have antipsychotic effects.


2015 ◽  
Vol 396 (3) ◽  
pp. 261-275 ◽  
Author(s):  
Miroslaw Ksiazek ◽  
Abdulkarim Y. Karim ◽  
Danuta Bryzek ◽  
Jan J. Enghild ◽  
Ida B. Thøgersen ◽  
...  

Abstract The genome of Tannerella forsythia, an etiological factor of chronic periodontitis, contains several genes encoding putative proteases. Here, we characterized a subtilisin-like serine protease of T. forsythia referred to as mirolase. Recombinant full-length latent promirolase [85 kDa, without its signal peptide (SP)] processed itself through sequential autoproteolytic cleavages into a mature enzyme of 40 kDa. Mirolase latency was driven by the N-terminal prodomain (NTP). In stark contrast to almost all known subtilases, the cleaved NTP remained non-covalently associated with mirolase, inhibiting its proteolytic, but not amidolytic, activity. Full activity was observed only after the NTP was gradually, and fully, degraded. Both activity and processing was absolutely dependent on calcium ions, which were also essential for enzyme stability. As a consequence, both serine protease inhibitors and calcium ions chelators inhibited mirolase activity. Activity assays using an array of chromogenic substrates revealed that mirolase specificity is driven not only by the substrate-binding subsite S1, but also by other subsites. Taken together, mirolase is a calcium-dependent serine protease of the S8 family with the unique mechanism of activation that may contribute to T. forsythia pathogenicity by degradation of fibrinogen, hemoglobin, and the antimicrobial peptide LL-37.


2013 ◽  
Vol 423-426 ◽  
pp. 667-673 ◽  
Author(s):  
Fan Wen Xin ◽  
Zhi Qiang Xu ◽  
Ya Nan Tu ◽  
Wei Yang ◽  
Xiang Yu Han ◽  
...  

For solving the problems of high energy consumption and high capacity of water-absorption, microwave dehydration technology of lignite was studied in this paper. A self-developed microwave system was used for the experiment on dehydration of lignite from eastern Inner Mongolia. It was proved that the condition of moisture migration was improved and microwave dehydration had a unique mechanism. By analyzing the effects of microwave powers, coal particle sizes, and lignite qualities on drying characteristics, it was found that the moisture decreased when the microwave power increased. it was found that the higher the power was, the faster the moisture decreased; the smaller the particle size was, the faster the moisture decreased; the less the lignite was, the faster the moisture decreased. Through the scanning electron microscope analysis, it was concluded that microwave had no significant effect on the smooth particles, and the fibrous particles and clusters particles tended to be smooth under the effect of microwave. Therefore, the interface of lignite was relatively stable, and not easy to reabsorb water after microwave.


Microbiology ◽  
2010 ◽  
Vol 156 (9) ◽  
pp. 2723-2733 ◽  
Author(s):  
Jing Wang ◽  
Gregg S. Pettis

Conjugal transfer of circular plasmids in Streptomyces involves a unique mechanism employing few plasmid-encoded loci and the transfer of double-stranded DNA by an as yet uncharacterized intercellular route. Efficient transfer of the circular streptomycete plasmid pIJ101 requires only two plasmid loci: the pIJ101 tra gene, and as a cis-acting function known as clt. Here, we compared the ability of the pIJ101 transfer apparatus to promote conjugal transfer of circular versus linear versions of the same replicon. While the pIJ101 tra locus readily transferred the circular form of the replicon, the linear version was transferred orders of magnitude less efficiently and all plasmids isolated from the transconjugants were circular, regardless of their original configuration in the donor. Additionally, relatively rare circularization of linear plasmids was detectable in the donor cells, which is consistent with the notion that this event was a prerequisite for transfer by TraB(pIJ101). Linear versions of this same replicon did transfer efficiently, in that configuration, from strains containing the conjugative linear plasmid SLP2. Our data indicate that functions necessary and sufficient for transfer of circular DNA were insufficient for transfer of a related linear DNA molecule. The results here suggest that the conjugation mechanisms of linear versus circular DNA in Streptomyces spp. are inherently different and/or that efficient transfer of linear DNA requires additional components.


1998 ◽  
Vol 273 (5) ◽  
pp. 3110-3116 ◽  
Author(s):  
Kung-Chia Young ◽  
Guey-Yueh Shi ◽  
Dung-Ho Wu ◽  
Li-Ching Chang ◽  
Bi-Ing Chang ◽  
...  

2021 ◽  
Vol 22 (12) ◽  
pp. 6339
Author(s):  
Jui-Hao Lee ◽  
Si-Yin Lin ◽  
Jen-Wei Liu ◽  
Shinn-Zong Lin ◽  
Horng-Jyh Harn ◽  
...  

Spinocerebellar ataxia type 3 (SCA3), a hereditary and lethal neurodegenerative disease, is attributed to the abnormal accumulation of undegradable polyglutamine (polyQ), which is encoded by mutated ataxin-3 gene (ATXN3). The toxic fragments processed from mutant ATXN3 can induce neuronal death, leading to the muscular incoordination of the human body. Some treatment strategies of SCA3 are preferentially focused on depleting the abnormal aggregates, which led to the discovery of small molecule n-butylidenephthalide (n-BP). n-BP-promoted autophagy protected the loss of Purkinje cell in the cerebellum that regulates the network associated with motor functions. We report that the n-BP treatment may be effective in treating SCA3 disease. n-BP treatment led to the depletion of mutant ATXN3 with the expanded polyQ chain and the toxic fragments resulting in increased metabolic activity and alleviated atrophy of SCA3 murine cerebellum. Furthermore, n-BP treated animal and HEK-293GFP-ATXN3-84Q cell models could consistently show the depletion of aggregates through mTOR inhibition. With its unique mechanism, the two autophagic inhibitors Bafilomycin A1 and wortmannin could halt the n-BP-induced elimination of aggregates. Collectively, n-BP shows promising results for the treatment of SCA3.


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