Recent advances in immobilization strategies for glycosidases

Glycans play important biological roles in cell‐to‐cell interactions, protection against pathogens, as well as in proper protein folding and stability, and are thus interesting targets for scientists. Although their mechanisms of action have been widely investigated and hypothesized, their biological functions are not well understood due to the lack of deglycosylation methods for large‐scale isolation of these compounds. Isolation of glycans in their native state is crucial for the investigation of their biological functions. However, current enzymatic and chemical deglycosylation techniques require harsh pretreatment and reaction conditions (high temperature and use of detergents) that hinder the isolation of native glycan structures. Indeed, the recent isolation of new endoglycosidases that are able to cleave a wider variety of linkages and efficiently hydrolyze native proteins has opened up the opportunity to elucidate the biological roles of a higher variety of glycans in their native state. As an example, our research group recently isolated a novel Endo‐β‐N‐acetylglucosaminidase from Bifidobacterium longum subsp. infantis ATCC 15697 (EndoBI‐1) that cleaves N‐N′‐diacetyl chitobiose moieties found in the N‐linked glycan (N‐glycan) core of high mannose, hybrid, and complex N‐glycans. This enzyme is also active on native proteins, which enables native glycan isolation, a key advantage when evaluating their biological activities. Efficient, stable, and economically viable enzymatic release of N‐glycans requires the selection of appropriate immobilization strategies. In this review, we discuss the state‐of‐the‐art of various immobilization techniques (physical adsorption, covalent binding, aggregation, and entrapment) for glycosidases, as well as their potential substrates and matrices. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:104–112, 2017     

产甲烷古菌研究进展

产甲烷古菌是一类严格厌氧的古菌,只能利用简单的化合物进行产甲烷生长。产甲烷古菌在地球生命起源和进化、全球气候变化、碳生物地球化学循环和农业废弃物资源化利用等领域,都起着至关重要的作用。系统了解产甲烷古菌的生物学特征,将有助于在这些基础和应用领域的研究工作。本文主要从生理生化特征、代谢途径、能量储存和系统分类等方面介绍产甲烷古菌的研究进展。     

Recent advances in synthetic glycoengineering for biological applications

Carbohydrates are involved in many important biological events such as protein maturation and trafficking, pathogen invasion, immune response, cell–cell communications, and so on. Synthetic and chemoenzymatic approaches for glycoengineering have emerged and been applied in perturbing and modulating the biological processes at the protein or cellular level. In this review, we summarize the recent advances in glycoengineering, including new strategies in chemoenzymatic synthesis of glycans, glycopeptides, glycoproteins, and other glycoconjugates. And, the progresses of cell-surface glyco-editing methods for gain of functions are also discussed.

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Recent advances in genetic modification systems for Actinobacteria

Applied Microbiology and Biotechnology - Actinobacteria are extremely important to human health, agriculture, and forests. Because of the vast differences of the characteristics of Actinobacteria,...     

Recent advances in intravital microscopy for preclinical research

Intravital microscopy (IVM) has revolutionized our understanding of single-cell behavior in complex tissues by enabling real-time observation of molecular and cellular processes in their natural environment. In preclinical research, IVM has emerged as a standard tool for mechanistic studies of therapy response and the rational design of new treatment strategies. Technological developments keep expanding the imaging depth and quality that can be achieved in living tissue, and the maturation of imaging modalities such as fluorescence and phosphorescence lifetime imaging facilitates co-registration of individual cell dynamics with metabolic tissue states. Correlation of IVM with mesoscopic and macroscopic imaging modalities further promotes the translation of mechanistic insights gained by IVM into clinically relevant information. This review highlights some of the recent advances in IVM that have made the transition from experimental optical techniques to practical applications in basic and preclinical research.     

Recent advances in chemiluminescence-based immunoassays for steroid hormones

Several formats of solid-phase separation techniques for the measurement of steroids and urinary steroid conjugates using chemiluminescence as an end point are described. These formats include: (1) immunoadsorption of second antibodies directed against the first antibody on solid support; (2) specific immunoadsorbents consisting of primary antibodies covalently coupled to polymer beads; (3) second antibody coupled to a polymer containing magnetic particles. In these assays a steroid-chemiluminescent marker conjugate serves as the labelled ligand, and highly specific homologous monoclonal antibodies are used to provide optimal specificity and rigorous standardization. These techniques enabled the direct measurement of steroid glucuronides in diluted urine and of steroids in plasma.     

Recent advances in lentiviral vectors for gene therapy

Lentiviral vectors (LVs),derived from human immunodeficiency virus,are powerful tools for modifying the genes of eukaryotic cells such as hematopoietic stem cel...     

Recent advances in drug therapy for epilepsy.

Recent advances in drug therapy for epilepsy have contributed to the reduction in the proportion of persons whose epilepsy is uncontrolled. New knowledge of the pharmacokinetics of phenytoin has led to a better understanding of the drug''s bioavailability and uses. Carbamazepine has recently been introduced for the treatment of generalized tonic-clonic and partial seizures. Clonazepam has been found of particular benefit in the treatment of absence and myoclonic seizures. Valproic acid is a promising antiepileptic drug with broad-spectrum activity, and is particularly useful in the treatment of absence and myoclonic seizures, although further clinical experience is required before it can supplant ethosuximide as the preferred drug for the treatment of absence seizures. Monitoring of the plasma concentration of antiepileptic drugs has added greatly to the achievement of optimal drug therapy and the prevention of toxic effects.