Green biomanufacturing promoted by automatic retrobiosynthesis planning and computational enzyme design

Biomanufacturing,which uses renewable resources as raw materials and uses biological processes to produce energy and chemicals,has long been regarded as a production model that replaces the unsustainable fossil economy.The construction of non-natural and efficient biosynthesis routes of chemicals is an important goal of green biomanufacturing.Traditional methods that rely on experience are difficult to support the realization of this goal.However,with the rapid development of information technology,the intelligence of biomanufacturing has brought hope to achieve this goal.Retrobiosynthesis and computational enzyme design,as two of the main technologies in intelligent biomanufacturing,have developed rapidly in recent years and have made great achievements and some representative works have demonstrated the great value that the integration of the two fields may bring.To achieve the final integration of the two fields,it is necessary to examine the information,methods and tools from a bird’s-eye view,and to find a feasible idea and solution for establishing a connection point.For this purpose,this article briefly reviewed the main ideas,methods and tools of the two fields,and put forward views on how to achieve the integration of the two fields.

二维铁电材料研究进展

近年来,随着微电子学的不断进步,电子器件正朝着小型化、集成化的趋势发展.但是在纳米尺度下,表面效应和尺寸效应将变得不可忽略,这便制约了传统块体铁电材料在现代工业中的应用.因此,没有小尺寸效应限制并且有着稳定自发极化的二维铁电材料成为了材料科学领域研究的重点之一.本文首先从铁电材料的分类出发,将其分为二维非范德华铁电材料和二维范德华铁电材料,并列举了各类别中已被实验报道的铁电材料,讨论了它们的发展和研究现状,并阐述了它们内在的极化机制和新奇的物理特性.这些新的二维铁电材料有望在未来的纳米级铁电应用中发挥重要的作用,使电子器件的高度集成成为可能.然后,本文综述了二维铁电器件的最新研究进展,包括铁电场效应晶体管(ferroelectric field effect transistor,FeFET)、铁电隧道结(ferroelectric tunnel junction,FTJ)和铁电突触,总结了各种器件性能,并阐述了相应的工作原理.最后,对二维铁电材料领域进行了展望,提出我们需要在理论模型、材料制备、电子器件的稳定性和界面效应等方面开展更深入研究的观点.

Density functional theory calculations on 2H-MoS_(2) monolayer for HCHO degradation:Piezoelectric-photocatalytic synergy

Formaldehyde(HCHO)is a common indoor gaseous pollutant,and long-term exposure to it may cause serious damage to the human immune system.Photocatalytic degradation of HCHO is a promising technique.However,most photocatalysts have the disadvantage of rapid recombination of photo-generated electron-hole pairs.In this work,the recombination of photogenerated electron holes was proposed to inhibit through the piezoelectric effect.A two-dimensional(2D)piezoelectric material,2H-MoS_(2),was selected to investigate the catalytic performance for HCHO degradation by the synergy of the piezoelectric and photocatalysis properties.The results show that the piezoelectric effect can induce the polarization in 2H-MoS_(2) and inhibit the recombination of photogenerated electron-hole pairs,thus improving the photogeneration of hydroxyl radicals for HCHO degradation.Therefore,the piezoelectric-photo-catalysis synergistic effect based on density functional theory(DFT)calculation was proposed to elucidate the HCHO degradation performance.This work could provide important guidance for the development of effective catalysts for HCHO degradation and the application of 2D piezoelectric materials.

Beclin 1 cleavage by caspase-3 inactivates autophagy and promotes apoptosis

Autophagy and apoptosis are both highly regulated biological processes that play essential roles in tissue homeostasis,development and diseases.Autophagy is also described as a mechanism of death pathways,however,the precise mechanism of how autophagy links to cell death remains to be fully understood.Beclin 1 is a dual regulator for both autophagy and apoptosis.In this study we found that Beclin 1 was a substrate of caspase-3 with two cleavage sites at positions 124 and 149,respectively.Furthermore,the autophagosome formation occurred,followed by the appearance of morphological hallmarks of apoptosis after staurosporine treatment.The cleavage products of Beclin 1 reduced autophagy and promoted apoptosis in HeLa cells and the cells in which Beclin 1 was stably knocked down by specific shRNA.In addition,the cleavage of Beclin 1 resulted in abrogating the interaction between Bcl-2 with Beclin 1,which could be blocked by z-VAD-fmk.Thus,our results suggest that the cleavage of Beclin 1 by caspase-3 may contribute to inactivate autophagy leading towards augmented apoptosis.

Parkin promotes proteasomal degradation of p62： implication of selective vulnerability of neuronal cells in the pathogenesis of Parkinson＇s disease

Mutations or inactivation of parkin, an E3 ubiquitin ligase, are associated with familial form or sporadic Parkinson＇s disease （PD）, respectively, which manifested with the selective vulnerability of neuronal ceils in substantia nigra （SN） and striatum （STR） regions. However, the underlying molecular mechanism linking parkin with the etiology of PD remains elusive. Here we report that p62, a critical regulator for protein quality control, inclusion body formation, selective autophagy and diverse signaling pathways, is a new substrate of parkin. P62 levels were increased in the SN and STR regions, but not in other brain regions in parkin knockout mice. Parkin directly interacts with and ubiquitinates p62 at the K13 to promote proteasomal degradation of p62 even in the absence of ATG5. Pathogenic mutations, knockdown of parkin or mutation of p62 at K13 prevented the degradation of p62. We further showed that parkin deficiency mice have pronounced loss of tyrosine hydroxylase positive neurons and have worse performance in motor test when treated with 6-hydroxydopamine hydrochloride in aged mice. These results suggest that, in addition to their critical role in regulating autophagy, p62 are subjected to parkin mediated proteasomal degradation and implicate that the dysregulation of parkin/p62 axis may involve in the selective vulnerability of neuronal cells during the onset of PD pathogenesis.