Enzyme–substrate interactions promote the self-assembly of amino acid derivatives into supramolecular hydrogels

2016 ◽  
Vol 4 (5) ◽  
pp. 844-851 ◽  
Author(s):  
Yanyan Xie ◽  
Renliang Huang ◽  
Wei Qi ◽  
Yuefei Wang ◽  
Rongxin Su ◽  
...  

The first example of enzyme-substrate interaction-promoted self-assembly was reported for the synthesis of supramolecular hydrogels from Fmoc-amino acids and amino acid esters in the presence of α-chymotrypsin.

1995 ◽  
Vol 73 (7) ◽  
pp. 1164-1174 ◽  
Author(s):  
Doris Freiesleben ◽  
Kurt Polborn ◽  
Christian Robl ◽  
Karlheinz Sünkel ◽  
Wolfgang Beck

Schiff bases from ferrocene aldehyde and α-amino acidates react with PdCl2 or Na2PdCl4 to give N,O-chelate complexes (2a–e, 3). The related N-ferrocenylmethylen-α-amino acid esters give, with Pd(OAc)2, cyclopalladated acetate-bridged complexes (4a,b). N,O-chelate complexes (5–7) are obtained from Na2PdCl4 with N-ferrocenylmethyl prolinate and-alaninate as well as with N,N-dibenzyl glycinate. The ethyl ester of N,N-dibenzylglycine and Pd(OAc)2 form the cyclopalladated acetate-bridged complex 8, while the ester of N-monobenzylglycine and Na2PdCl4 affords trans-PdCl2(L)2 with a monodentate N-coordinated ligand. The structures of 2a, 4a, 5, 7, and 9 were determined by X-ray diffraction. Keywords: ferrocene, amino acids, palladium(II) complexes, crystal structures.


Synlett ◽  
2020 ◽  
Author(s):  
Xiaohua Liu ◽  
Yi Li ◽  
Hao Pan ◽  
Wang-Yuren Li ◽  
Xiaoming Feng

AbstractAn asymmetric organocatalytic nucleophilic aromatic substitution reaction of azlactones with electron-deficient aryls was established. A variety of α-aryl α-alkyl α-amino acid esters and peptides were obtained in decent yields and stereoselectivities. A new bifunctional catalytic mode involving charge-transfer interaction and hydrogen bonding is proposed to explain the enantioselectivity.


1973 ◽  
Vol 4 (40) ◽  
pp. no-no
Author(s):  
D. A. HOOGWATER ◽  
D. N. REINHOUDT ◽  
T. S. LIE ◽  
J. J. GUNNEWEG ◽  
H. C. BEYERMAN

2021 ◽  
Author(s):  
Bharti Koshti ◽  
Ramesh Singh ◽  
Vivekshinh Kshtriya ◽  
Shanka Walia ◽  
Dhiraj Bhatia ◽  
...  

<p>.<br></p><p>The self-assembly of single amino acids is very important topic of research since there are plethora of diseases like phenylketonuria, tyrosinemia, hypertryptophanemia, hyperglycinemia, cystinuria and maple syrup urine disease to name a few which are caused by the accumulation or excess of amino acids. These are in-born errors of metabolisms (IEM’s) which are caused due to the deficiency of enzymes involved in catabolic pathways of these enzymes. Hence, it is very pertinent to understand the fate of these excess amino acids in the body and their self-assembling behaviour at molecular level. From the previous literature reports it may be surmised that the single amino acids like Phenylalanine, Tyrosine, Tryptophan, Cysteine and Methionine assemble to amyloid like structures, and hence have important implications in the pathophysiology of IEM’s like phenylketonuria, tyrosinemia, hypertryptophanemia, cystinuria and hypermethioninemia respectively. In this manuscript we report the self-assembly of lysine hydrocholride to fiber like structures in deionized water. It could be observed that lysine assemble to globular structures in fresh condition and then gradually changes to fiber like morphologies by self-association over time after 24 hours. These fibers gradually change to tubular morphologies after 3 day followed by fractal irregular morphologies in 10 and 15 days respectively. Notably, lysine exists as positively charged amino acid at physiological pH and the amine groups in lysine remain protonated. Hence, the self-assembling properties of lysine hydrochloride in deionized water is also pertinent and give insights into the fate of this amino acid in body in case it remains unmetabolized. Further, MTT assays were done to analyse the toxicities of these aggregates and the assay suggest their cytotoxic nature on SHSY5Y neural cell lines. Hence, the aggregation of lysine may be attributed to the pathological symptoms caused in diseases like hyperlysinemia which is associated with the neurological problems like seizures and short-term memory as observed in case of amyloid diseases like Parkinson’s and Alzheimer’s to name a few.</p>


2020 ◽  
Vol 56 (17) ◽  
pp. 2642-2645 ◽  
Author(s):  
Zhi-Fang Yang ◽  
Chang Xu ◽  
Xing Zheng ◽  
Xingang Zhang

A nickel-catalyzed tandem reaction of N-vinylamides with arylboronic acids and bromodifluoroacetate has been developed. The reaction efficiently furnishes a series of protected α,α-difluoro-γ-amino acid esters.


RSC Advances ◽  
2017 ◽  
Vol 7 (17) ◽  
pp. 10158-10174 ◽  
Author(s):  
Lorenzo Biancalana ◽  
Marco Bortoluzzi ◽  
Eleonora Ferretti ◽  
Mohammad Hayatifar ◽  
Fabio Marchetti ◽  
...  

We describe the synthesis of rare coordination compounds of early transition metals with α-amino acids and α-amino acid esters, the unusual C–C dimerization ofl-proline, and the stabilization of reactive α-ammonium acylchloride cations.


2010 ◽  
Vol 92 (8) ◽  
pp. 819-825 ◽  
Author(s):  
D.A. Hoogwater ◽  
D.N. Reinhoudt ◽  
T.S. Lie ◽  
J.J. Gunneweg ◽  
H.C. Beyerman

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