Semi-rational protein engineering of a novel esterase from Bacillus aryabhattai (BaCE) for resolution of (R,S)-ethyl indoline-2-carboxylate to prepare (S)-indoline-2-carboxylic acid

2022 ◽  
pp. 105602
Author(s):  
Hongjun Zhang ◽  
Zeguang Cheng ◽  
Litian Wei ◽  
Xinjun Yu ◽  
Zhao Wang ◽  
...  
Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 206 ◽  
Author(s):  
Yinjun Zhang ◽  
Jialin Chen ◽  
Changsheng Chen ◽  
Shijin Wu

The strain screened from sludge can selectively hydrolyze (S)-ethyl indoline-2-carboxylate to produce (S)-indoline-2-carboxylic acid. It was identified as the Bacillus aryabhattai strain based on its morphology, metabolism, and 16S rDNA sequence analysis. Glucose and yeast powder were used as the best carbon and nitrogen sources to cultured cells with an initial pH of seven. Subsequently, we optimized the key parameters for selective hydrolysis. Finally, when the substrate concentration had reached 3%, with a 35 °C water bath, a pH of seven, and a speed of 600 rpm, the e.e.p value attained 96% with a 33% yield. Thus, we had developed a new method for producing (S)-indoline-2-carboxylic acid that used whole microbial cells as the biocatalyst.


2019 ◽  
Vol 476 (24) ◽  
pp. 3835-3847 ◽  
Author(s):  
Aliyath Susmitha ◽  
Kesavan Madhavan Nampoothiri ◽  
Harsha Bajaj

Most Gram-positive bacteria contain a membrane-bound transpeptidase known as sortase which covalently incorporates the surface proteins on to the cell wall. The sortase-displayed protein structures are involved in cell attachment, nutrient uptake and aerial hyphae formation. Among the six classes of sortase (A–F), sortase A of S. aureus is the well-characterized housekeeping enzyme considered as an ideal drug target and a valuable biochemical reagent for protein engineering. Similar to SrtA, class E sortase in GC rich bacteria plays a housekeeping role which is not studied extensively. However, C. glutamicum ATCC 13032, an industrially important organism known for amino acid production, carries a single putative sortase (NCgl2838) gene but neither in vitro peptide cleavage activity nor biochemical characterizations have been investigated. Here, we identified that the gene is having a sortase activity and analyzed its structural similarity with Cd-SrtF. The purified enzyme showed a greater affinity toward LAXTG substrate with a calculated KM of 12 ± 1 µM, one of the highest affinities reported for this class of enzyme. Moreover, site-directed mutation studies were carried to ascertain the structure functional relationship of Cg-SrtE and all these are new findings which will enable us to perceive exciting protein engineering applications with this class of enzyme from a non-pathogenic microbe.


1969 ◽  
Vol 21 (02) ◽  
pp. 294-303 ◽  
Author(s):  
H Mihara ◽  
T Fujii ◽  
S Okamoto

SummaryBlood was injected into the brains of dogs to produce artificial haematomas, and paraffin injected to produce intracerebral paraffin masses. Cerebrospinal fluid (CSF) and peripheral blood samples were withdrawn at regular intervals and their fibrinolytic activities estimated by the fibrin plate method. Trans-form aminomethylcyclohexane-carboxylic acid (t-AMCHA) was administered to some individuals. Genera] relationships were found between changes in CSF fibrinolytic activity, area of tissue damage and survival time. t-AMCHA was clearly beneficial to those animals given a programme of administration. Tissue activator was extracted from the brain tissue after death or sacrifice for haematoma examination. The possible role of tissue activator in relation to haematoma development, and clinical implications of the results, are discussed.


Acta Naturae ◽  
2010 ◽  
Vol 2 (3) ◽  
pp. 47-61 ◽  
Author(s):  
V I Tishkov ◽  
S S Savin ◽  
A S Yasnaya

2020 ◽  
Author(s):  
Aleksandra Balliu ◽  
Aaltje Roelofje Femmigje Strijker ◽  
Michael Oschmann ◽  
Monireh Pourghasemi Lati ◽  
Oscar Verho

<p>In this preprint, we present our initial results concerning a stereospecific Pd-catalyzed protocol for the C3 alkenylation and alkynylation of a proline derivative carrying the well utilized 8‑aminoquinoline directing group. Efficient C–H alkenylation was achieved with a wide range of vinyl iodides bearing different aliphatic, aromatic and heteroaromatic substituents, to furnish the corresponding C3 alkenylated products in good to high yields. In addition, we were able show that this protocol can also be used to install an alkynyl group into the pyrrolidine scaffold, when a TIPS-protected alkynyl bromide was used as the reaction partner. Furthermore, two different methods for the removal of the 8-aminoquinoline auxiliary are reported, which can enable access to both <i>cis</i>- and <i>trans</i>-configured carboxylic acid building blocks from the C–H alkenylation products.</p>


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