Immobilization of Lipases by Adsorption on Hydrophobic Supports: Modulation of Enzyme Properties in Biotransformations in Anhydrous Media

2020 ◽  
pp. 143-158 ◽  
Author(s):  
Gloria Fernandez-Lorente ◽  
Javier Rocha-Martín ◽  
Jose M. Guisan
Keyword(s):  
Enzyme Properties ◽  
Hydrophobic Supports

scholarly journals In Vitro Characterization of the Enzyme Properties of the Phospholipid N-Methyltransferase PmtA from Agrobacterium tumefaciens

2009 ◽  
Vol 191 (7) ◽  
pp. 2033-2041 ◽  
Author(s):  
Meriyem Aktas ◽  
Franz Narberhaus
Keyword(s):  
Agrobacterium Tumefaciens ◽  
In Vitro Assay ◽  
Enzyme Properties ◽  
Vitro Assay ◽  
Plant Infection ◽  
In Vitro Characterization ◽  
End Products ◽  
And Control

ABSTRACT Agrobacterium tumefaciens requires phosphatidylcholine (PC) in its membranes for plant infection. The phospholipid N-methyltransferase PmtA catalyzes all three transmethylation reactions of phosphatidylethanolamine (PE) to PC via the intermediates monomethylphosphatidylethanolamine (MMPE) and dimethylphosphatidylethanolamine (DMPE). The enzyme uses S-adenosylmethionine (SAM) as the methyl donor, converting it to S-adenosylhomocysteine (SAH). Little is known about the activity of bacterial Pmt enzymes, since PC biosynthesis in prokaryotes is rare. In this article, we present the purification and in vitro characterization of A. tumefaciens PmtA, which is a monomeric protein. It binds to PE, the intermediates MMPE and DMPE, the end product PC, and phosphatidylglycerol (PG) and phosphatidylinositol. Binding of the phospholipid substrates precedes binding of SAM. We used a coupled in vitro assay system to demonstrate the enzymatic activity of PmtA and to show that PmtA is inhibited by the end products PC and SAH and the antibiotic sinefungin. The presence of PG stimulates PmtA activity. Our study provides insights into the catalysis and control of a bacterial phospholipid N-methyltransferase.

Improvement of catalytical properties of two invertases highly tolerant to sucrose after expression in Pichia pastoris . Effect of glycosylation on enzyme properties

2016 ◽  
Vol 83 ◽  
pp. 48-56 ◽  
Author(s):  
Ara Itzel Pérez de los Santos ◽  
Maribel Cayetano-Cruz ◽  
Marina Gutiérrez-Antón ◽  
Alejandro Santiago-Hernández ◽  
Miguel Plascencia-Espinosa ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Enzyme Properties

Structure and enzyme properties ofZabrotes subfasciatus α-amylase

2006 ◽  
Vol 61 (2) ◽  
pp. 77-86 ◽  
Author(s):  
Patrícia B. Pelegrini ◽  
André M. Murad ◽  
Maria F. Grossi-de-Sá ◽  
Luciane V. Mello ◽  
Luiz A.S. Romeiro ◽  
...  
Keyword(s):  
Enzyme Properties

scholarly journals Gene editing with CRISPR-Cas12a guides possessing ribose-modified pseudoknot handles

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eman A. Ageely ◽  
Ramadevi Chilamkurthy ◽  
Sunit Jana ◽  
Leonora Abdullahu ◽  
Daniel O’Reilly ◽  
...  
Keyword(s):  
Gene Editing ◽  
Human Cells ◽  
Model Organisms ◽  
Enzyme Properties ◽  
Chemical Compatibility ◽  
Modified Nucleotides ◽  
Chemical Modifications ◽  
Pseudoknot Structure ◽  
Therapeutic Development

AbstractCRISPR-Cas12a is a leading technology for development of model organisms, therapeutics, and diagnostics. These applications could benefit from chemical modifications that stabilize or tune enzyme properties. Here we chemically modify ribonucleotides of the AsCas12a CRISPR RNA 5′ handle, a pseudoknot structure that mediates binding to Cas12a. Gene editing in human cells required retention of several native RNA residues corresponding to predicted 2′-hydroxyl contacts. Replacing these RNA residues with a variety of ribose-modified nucleotides revealed 2′-hydroxyl sensitivity. Modified 5′ pseudoknots with as little as six out of nineteen RNA residues, with phosphorothioate linkages at remaining RNA positions, yielded heavily modified pseudoknots with robust cell-based editing. High trans activity was usually preserved with cis activity. We show that the 5′ pseudoknot can tolerate near complete modification when design is guided by structural and chemical compatibility. Rules for modification of the 5′ pseudoknot should accelerate therapeutic development and be valuable for CRISPR-Cas12a diagnostics.

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