A simple and versatile method for the preparation of functional enzyme-gold nanoparticle conjugates using "click" chemistry has been developed. In a copper-catalyzed 1,2,3-triazole cycloaddition, an acetylene-functionalized Thermomyces lanuginosus lipase has been attached to azide-functionalized water-soluble gold nanoparticles under retention of enzymatic activity. The products have been characterized by gel electrophoresis and a fluorometric lipase activity assay. It is estimated that the equivalent of approximately seven fully active lipase molecules are attached to each nanoparticle.
Variants of lipase were attached to gold nanoparticles (NPs) and their enzymatic activity was studied. The two bioengineered lipase variants have been prepared with biotin groups attached to different residues on the protein outer surface. The biotinylation was evidenced by denaturing polyacrylamide gel electrophoresis and quantified by the ([2-(4'-hydroxyazobenzene)]benzoic acid spectrophotometric test. NPs of 14 +/- 1 nm diameter coated with thiolated-polyethylene glycol ligands containing controlled proportions of biotin moieties have been prepared and characterized by transmission electron microscopy, UV-vis spectroscopy, small angle neutron scattering, and elemental analysis. These biotin-functionalized NPs were conjugated to lipase using streptavidin as a linker molecule. Enzyme activity assays on the lipase-nanoparticle conjugates show that the lipase loading and activity of the NPs can be controlled by varying the percentage of biotin groups in the particle protecting coat. The lipase-NP conjugates prepared using one variant display higher activity than those prepared using the other variant, demonstrating orientation-dependent enzyme activity. Cryogenic transmission electron microscopy was used to visualize the enzymatic activity of lipase-NP on well-defined lipid substrates. It was found that lipase-coated NPs are able to digest the substrates in a different manner in comparison to the free lipase.
A series of N-formyl-O-acyl-β-phenylserine derivatives 1b -7b were prepared by the interaction of N-acylβ-phenylserine ethyl esters 1a-7a with formic acid in presence of 1.5% HF. One-pot acyl group N→O migration followed N-formylation under elaborated reaction conditions. 1.96(CH 2 ,q, J = 8.0) 3.97 q, 0.73 t, 7.42 m J = 4.0, 5.0 J = 5.0 J = 4.0, 9.0 J = 9.0 0.98(CH 3 , t, J = 7.0) J = 7.0 J = 7.0 3a CDCl 3 7.20 s 5.09 d, b ) 4.71 dd, 6.29 d, 2.02(CH 2 , q, J = 6.5) 4.04 q, 0.91 t, J = 3.0 J = 3.0, 9.0 J = 8.0 1.11(CH 3 , t, J = 7.0) J = 7.0 J = 7.3 4a (CD 3 )CO 7.06 -5.20 d, 6.18 d, 4.67 dd, 7.69 d, 2.09(CH 2 , m) 3.97 q, 0.8 t, 7.42 m J = 3.0 J = 5.0 J = 3.0, 10.0 J = 10.0 3.58(CH 2 Br, m) J = 7.0 J = 7.0 5a (CD 3 ) 2 CO 7.03 -5.15 d, b ) 4.58 dd, b ) 3.39(CH 2 , s) 3.99 q, 1.06 t, 7.24 m J = 3.2 J = 3.2; 9.0 7.03 -7.24(C 6 H 5, m) J = 7.1 J = 7.1 6a DMSO-d 6 7.09 -5.0 m b ) 4.71 dd, 5.27 d, 2.53(CH 2 , d, J = 7.0) 3.98 q, 1.1 t, 7.74 m J = 5.0, 9.0 J = 8.0 4.20(CH ,t, J = 7.0) J = 7.0 J = 7.0 7.09 -7.74 [(C 6 H 4 ) 2 C,m] 6a CDCl 3 7.09 -5.22 d, b ) 4.98 dd, 6.27 d, 2.56(CH 2 , q, J = 8,0) 4.14 q, 1.18 t, 7.83 m J = 3.0 J = 3.0, 9.0 J = 8.8 4.37(CH, t, J = 8.0) J = 7.0 J = 7.0 7.09 -7.83 [(C 6 H 4 ) 2 C, m] 7a CDCl 3 7.11-5.04 dd, b ) 4.94 dd 6.11 d, 2.56(CH 2 , d, J = 7.0) 3.98 q, 1.04 t, 7.71 m J = 3.0, 7.0 J = 3.0, 7.0 J = 7.0 4.39(CH, t, J = 7.0) J = 7.0 J = 7.0 7.11 -7.71 [(C 6 H 4 ) 2 C, m] a ) Residues R are the same as in Scheme 1 b ) Overlapped with other signals
Synthesis of N- and O-acyl derivatives of ᴅʟ-serine and threo-ᴅʟ-phenylserine was accomplished by a regioselective acylation of the corresponding amino acid. The residues introduced into amino acid structure contain hydrophobic long chain or aromatic, namely lauroyl, myristoyl and phenylacetyl moieties. The fungicidal activity against six strains of fungi was studied. Several compounds were found to be effective against growth of fungi, and Omyristoyl- ᴅʟ-serine 2 and N-phenylacetyl-threo-ᴅʟ-phenylserine 8 completely inhibited the growth of the mycelium of the fungus Verticillium dahliae.
A series of N-formyl-O-acyl-β-phenylserine derivatives 1b -7b were prepared by the interaction of N-acylβ-phenylserine ethyl esters 1a-7a with formic acid in presence of 1.5% HF. One-pot acyl group N→O migration followed N-formylation under elaborated reaction conditions. 1.96(CH 2 ,q, J = 8.0) 3.97 q, 0.73 t, 7.42 m J = 4.0, 5.0 J = 5.0 J = 4.0, 9.0 J = 9.0 0.98(CH 3 , t, J = 7.0) J = 7.0 J = 7.0 3a CDCl 3 7.20 s 5.09 d, b ) 4.71 dd, 6.29 d, 2.02(CH 2 , q, J = 6.5) 4.04 q, 0.91 t, J = 3.0 J = 3.0, 9.0 J = 8.0 1.11(CH 3 , t, J = 7.0) J = 7.0 J = 7.3 4a (CD 3 )CO 7.06 -5.20 d, 6.18 d, 4.67 dd, 7.69 d, 2.09(CH 2 , m) 3.97 q, 0.8 t, 7.42 m J = 3.0 J = 5.0 J = 3.0, 10.0 J = 10.0 3.58(CH 2 Br, m) J = 7.0 J8 4.37(CH, t, J = 8.0) J = 7.0 J = 7.0 7.09 -7.83 [(C 6 H 4 ) 2 C, m] 7a CDCl 3 7.11-5.04 dd, b ) 4.94 dd 6.11 d, 2.56(CH 2 , d, J = 7.0) 3.98 q, 1.04 t, 7.71 m J = 3.0, 7.0 J = 3.0, 7.0 J = 7.0 4.39(CH, t, J = 7.0) J = 7.0 J = 7.0 7.11 -7.71 [(C 6 H 4 ) 2 C, m] a ) Residues R are the same as in Scheme 1 b ) Overlapped with other signals Tab. 5 1 H NMR spectra (chemical shifts δ in ppm, multiplicity, coupling constants J in Hz) of compounds 1b-7b Comp. C 6 H 5 CH (OCO -R b ) -CH (NH-OCH)CO 2 CH 2 -CH 3 a ) 1b 7.18 s 6.00 d, 1.62 s 4.77 dd, 8.42 d, 8.2 s 3.91 q, 0.93 t, J = 5.0 J = 5.0, 9.0 J = 9.0 J = 7.0 J = 7.0 2b 7.20 s 6.25 d 1.64 s 5.11 dd, 7.63 d, 8.11 s 4.01 q, 0.91 t J = 5.0 J = 5.0, 9.0 J = 9.0 J = 7,0 J = 7.0 3b 7.16 -6.27 d, 2.02 (CH 2 , q, J = 7.0) 4.98 dd, c) 8.09 s 4.02 q, 0.87 t, 7.49 m J = 5.0 1.07(CH 3, t, J = 7.0) J = 5.0, 9.0 J = 7.0 J = 7.0 4b 7.14 -6.24 d, 2.73(CH 2 , t, J = 6.5) 5.02 dd, 7.68 d, 8.13 s 4.04 q, 0.90 t, 7.44 m J = 5.0 3.42(CH 2 Br, t, J = 6.5) J = 5.0, 8.0 J = 8.0 J = 7.0 J = 7.0 5b 6.98-6.27 d, 3.42(CH 2 , s) 4.99 dd, 7.51 d, 8.10 s 3.98 q, 0.91 t, 7.31 m J = 4.4 6.98 -7.31(C 6 H 5 , m) J = 4.4, 10.0 J = 10.0 J = 7.0 J = 7.0 6b 7.12 -6.23 d, 2.56(CH 2 , k, J = 8.0) 4.98 d, 7.60 d, 8,13 s 4.05 q, 0.95 t, 7.48 m J = 4.5 4.35(CH, t, J = 8.0) J = 4.5, 9.0 J = 9,0 J = 7.0 J = 7.0 7.12-7.,48[(C 6 H 4 ) 2 C, m] 7b 7.04 -6.21 d, 2.56(CH 2 , t, J = 8.0) 5.23 dd c) 8.15 s 4.09 q, 1.14 t, 7.73 m J = 7.0 4.33(CH, t, J = 8.0) J = 4.5, 9.0 J = 7.0 J = 7.0 7.04 -7.73[(C 6 H 4 ) 2 C, m] a ) The spectra were recorded in (CD 3 ) 2 CO except for 1b in DMSO-d 6 ; b ) The radicals R are the same as in Scheme 1 c ) Overlapped with other signals
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.