scholarly journals Versatile Labeling and Detection of Endogenous Proteins Using Tag-Assisted Split Enzyme Complementation

2021 ◽  
Author(s):  
Suraj Makhija ◽  
David Brown ◽  
Rachel M. Rudlaff ◽  
Julia K. Doh ◽  
Struan Bourke ◽  
...  
Keyword(s):  
Endogenous Proteins

scholarly journals Spontaneous Cleavages of a Heterologous Protein, the CenA Endoglucanase of Cellulomonas fimi, in Escherichia coli

2021 ◽  
Vol 14 ◽  
pp. 117863612110246
Author(s):  
Cheuk Yin Lai ◽  
Ka Lun Ng ◽  
Hao Wang ◽  
Chui Chi Lam ◽  
Wan Keung Raymond Wong
Keyword(s):  
Escherichia Coli ◽  
Cellulolytic Bacterium ◽  
Systematic Screening ◽  
Cellulomonas Fimi ◽  
E Coli ◽  
Substrate Complex ◽  
Enzyme Substrate ◽  
Glycosylation Sites ◽  
Endogenous Proteins ◽  
Cellulose Binding

CenA is an endoglucanase secreted by the Gram-positive cellulolytic bacterium, Cellulomonas fimi, to the environment as a glycosylated protein. The role of glycosylation in CenA is unclear. However, it seems not crucial for functional activity and secretion since the unglycosylated counterpart, recombinant CenA (rCenA), is both bioactive and secretable in Escherichia coli. Using a systematic screening approach, we have demonstrated that rCenA is subjected to spontaneous cleavages (SC) in both the cytoplasm and culture medium of E. coli, under the influence of different environmental factors. The cleavages were found to occur in both the cellulose-binding (CellBD) and catalytic domains, with a notably higher occurring rate detected in the former than the latter. In CellBD, the cleavages were shown to occur close to potential N-linked glycosylation sites, suggesting that these sites might serve as ‘attributive tags’ for differentiating rCenA from endogenous proteins and the points of initiation of SC. It is hypothesized that glycosylation plays a crucial role in protecting CenA from SC when interacting with cellulose in the environment. Subsequent to hydrolysis, SC would ensure the dissociation of CenA from the enzyme-substrate complex. Thus, our findings may help elucidate the mechanisms of protein turnover and enzymatic cellulolysis.

scholarly journals Split-wrmScarlet and split-sfGFP: Tools for faster, easier fluorescent l abeling of endogenous proteins in Caenorhabditis elegans

Genetics ◽  
2021 ◽  
Author(s):  
Jérôme Goudeau ◽  
Catherine S Sharp ◽  
Jonathan Paw ◽  
Laura Savy ◽  
Manuel D Leonetti ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Fluorescent Labeling ◽  
Large Fragment ◽  
C Elegans ◽  
High Affinity ◽  
Red Fluorescent Proteins ◽  
Invaluable Tool ◽  
Endogenous Proteins ◽  
Fluorescent Tags

Abstract We create and share a new red fluorophore, along with a set of strains, reagents and protocols, to make it faster and easier to label endogenous C. elegans proteins with fluorescent tags. CRISPR-mediated fluorescent labeling of C. elegans proteins is an invaluable tool, but it is much more difficult to insert fluorophore-size DNA segments than it is to make small gene edits. In principle, high-affinity asymmetrically split fluorescent proteins solve this problem in C. elegans: the small fragment can quickly and easily be fused to almost any protein of interest, and can be detected wherever the large fragment is expressed and complemented. However, there is currently only one available strain stably expressing the large fragment of a split fluorescent protein, restricting this solution to a single tissue (the germline) in the highly autofluorescent green channel. No available C. elegans lines express unbound large fragments of split red fluorescent proteins, and even state-of-the-art split red fluorescent proteins are dim compared to the canonical split-sfGFP protein. In this study, we engineer a bright, high-affinity new split red fluorophore, split-wrmScarlet. We generate transgenic C. elegans lines to allow easy single-color labeling in muscle or germline cells and dual-color labeling in somatic cells. We also describe a novel expression strategy for the germline, where traditional expression strategies struggle. We validate these strains by targeting split-wrmScarlet to several genes whose products label distinct organelles, and we provide a protocol for easy, cloning-free CRISPR/Cas9 editing. As the collection of split-FP strains for labeling in different tissues or organelles expands, we will post updates at doi.org/10.5281/zenodo.3993663

scholarly journals Biomimetic recombinant of red blood cell membranes for improved photothermal therapy

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Pengkai Wu ◽  
Xing Jiang ◽  
Shuai Yin ◽  
Ying Yang ◽  
Tianqing Liu ◽  
...  
Keyword(s):  
Immune Escape ◽  
Green Technology ◽  
Structural Failure ◽  
Pharmacokinetics And Pharmacodynamics ◽  
Coated Nanoparticles ◽  
Rbc Membrane ◽  
Delivery Platform ◽  
Red Blood Cell Membranes ◽  
Endogenous Proteins ◽  
Active Substances

Abstract Background RBC membrane derived nanoparticles (NPs) represent an emerging platform with prolonged circulation capacity for the delivery of active substances. For functionalize derived RBCs NPs, various strategies, such as biomimetic rebuilding of RBCs, chemical modification or inserting ligands, have been carried out to improve their performance. However, one potential adverse effect for these methods is the structural failure of membrane proteins, consequently affecting its original immune escape function. Results In this study, we reported a green technology of “disassembly-reassembly” to prepare biomimetic reconstituted RBCs membrane (rRBCs) by separating the endogenous proteins and lipids from nature RBC membrane. IR780 iodide was used as a pattern drug to verify the property and feasibility of rRBCs by constructing IR780@rRBC NPs with IR780@RBC NPs and free IR780 as controls. The results demonstrated the superiority of IR780@rRBC NPs in toxicity, stability, pharmacokinetics and pharmacodynamics compared with IR780@rRBC and free IR780. Conclusions The reported “disassembly-reassembly” strategy shows great potential to produce controllable and versatile rRBC membrane-inspired delivery platform, which may be used to overcome the deficiency of functionalization in cell membrane coated nanoparticles . Graphic abstract

scholarly journals NeissLock provides an inducible protein anhydride for covalent targeting of endogenous proteins

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Arne H. A. Scheu ◽  
Sheryl Y. T. Lim ◽  
Felix J. Metzner ◽  
Shabaz Mohammed ◽  
Mark Howarth
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Binding Protein ◽  
Growth Factor Receptor ◽  
Molecular Engineering ◽  
Nucleophilic Attack ◽  
High Yield ◽  
Protein Chemistry ◽  
Transforming Growth Factor Α ◽  
Endogenous Proteins

AbstractThe Neisseria meningitidis protein FrpC contains a self-processing module (SPM) undergoing autoproteolysis via an aspartic anhydride. Herein, we establish NeissLock, using a binding protein genetically fused to SPM. Upon calcium triggering of SPM, the anhydride at the C-terminus of the binding protein allows nucleophilic attack by its target protein, ligating the complex. We establish a computational tool to search the Protein Data Bank, assessing proximity of amines to C-termini. We optimize NeissLock using the Ornithine Decarboxylase/Antizyme complex. Various sites on the target (α-amine or ε-amines) react with the anhydride, but reaction is blocked if the partner does not dock. Ligation is efficient at pH 7.0, with half-time less than 2 min. We arm Transforming Growth Factor-α with SPM, enabling specific covalent coupling to Epidermal Growth Factor Receptor at the cell-surface. NeissLock harnesses distinctive protein chemistry for high-yield covalent targeting of endogenous proteins, advancing the possibilities for molecular engineering.

Degradation of endogenous proteins and internalized asialofetuin in primary cultured hepatocytes of rats

1989 ◽  
Vol 21 (5) ◽  
pp. 483-495 ◽  
Author(s):  
Hisanori Kato ◽  
Shin-Ichiro Takahashi ◽  
Akio Takenaka ◽  
Ryuhei Funabiki ◽  
Tadashi Noguchi ◽  
...  
Keyword(s):  
Cultured Hepatocytes ◽  
Primary Cultured Hepatocytes ◽  
Endogenous Proteins

Change with donor age in the degradation rate of endogenous proteins of mouse hepatocytes in primary culture

1992 ◽  
Vol 15 (2) ◽  
pp. 181-188 ◽  
Author(s):  
Tadao Ikeda ◽  
Akihito Ishigamia ◽  
Kaijiro Anzai ◽  
Sataro Goto
Keyword(s):  
Primary Culture ◽  
Degradation Rate ◽  
Donor Age ◽  
Mouse Hepatocytes ◽  
Endogenous Proteins
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