Chemical modification of crystal-like mesoporous phenylene-silica with amino group

2008 ◽  
pp. 841-843 ◽  
Author(s):  
Masataka Ohashi ◽  
Mahendra P. Kapoor ◽  
Shinji Inagaki
Keyword(s):  
Chemical Modification ◽  
Amino Group

scholarly journals Chemical modification of the human ether-a-go-go-related gene (HERG) K+ current by the amino-group reagent trinitrobenzene sulfonic acid

2006 ◽  
Vol 29 (4) ◽  
pp. 310-317 ◽  
Author(s):  
Su-Hyun Jo ◽  
Se-Young Choi ◽  
Ji-Hyun Yun ◽  
Young-Sang Koh ◽  
Won-Kyung Ho ◽  
...  
Keyword(s):  
Chemical Modification ◽  
Sulfonic Acid ◽  
Trinitrobenzene Sulfonic Acid ◽  
Amino Group ◽  
Related Gene ◽  
K Current

scholarly journals Synthesis of acyl derivatives of thiazolo[5.4-b]indole

2019 ◽  
Vol 55 (4) ◽  
pp. 436-441
Author(s):  
D. V. Lopatik ◽  
Z. I. Kuvaeva ◽  
O. M. Bondareva ◽  
V. E. Naidenov ◽  
L. Yu. Tychinskaya
Keyword(s):  
Chemical Modification ◽  
Free Amino ◽  
Amino Group ◽  
Therapeutic Activity ◽  
Functional Derivatives ◽  
Derivatives Of ◽  
Acyl Derivatives

2-Amino-4-acetylthiazolo[5,4-b]indole and its bromosubstituted analogue contain a free amino group and are initial compounds for chemical modification in order to obtain on their basis functional derivatives having high therapeutic activity. By the interaction of these 2-aminо-4-acetylthiazolo[5,4-b]indoles with succinic and maleic anhydrides, the corresponding imides and amides were obtained, which are of interest for use in order to create on their basis antihypoxic and actoprotective agents.

scholarly journals Chemical modification of amino groups and guanidino groups of trypsin. Preparation of stable and soluble derivatives

1975 ◽  
Vol 147 (1) ◽  
pp. 71-81 ◽  
Author(s):  
A Nureddin ◽  
T Inagami
Keyword(s):  
Chemical Modification ◽  
Peptide Bond ◽  
Enzymic Activity ◽  
Native Enzyme ◽  
Amino Group ◽  
Amino Groups ◽  
Appreciable Change ◽  
Neutral Ph ◽  
Arginine Residues ◽  
Esterolytic Activity

1. Isoionic chemical modification of amino groups of trypsin (EC 3.4.21.4) was studied for the purpose of obtaining a well-defined modified trypsin with minimum changes in physicochemical properties and with sufficient stability at neutral pH. Acetamidination with methyl acetimidate hydrochloride proceeded very rapidly at pH9.8 and 5degrees C and all 14 epsilon-amino groups were modified in 2h. The reaction was limited to epsilon-amino groups. The α-amino group of N-terminal isoleucine was modified only by repeated reactions in the presence of 5.5 M-guanidine or 8 M-urea. 2. The epsilon-acetamidinated derivative of β-trypsin retained enzymic activity at values comparable with those of native enzyme tested with α-N-benzoyl-L-arginine ethyl ester and α-N-benzoyl-L-arginine p-nitroanilide as substrates; it also showed substrate activation comparable with that of native enzyme. The acetamidination of α-trypsin resulted in approx. 50% decrease in its esterolytic activity. 3. The epsilon-acetamidinated β-trypsin was very stable at pH8 and 25degrees C in the absence of Ca2+. The activity of 0.04% (W/V) enzyme solution remained practically unchanged for 10h, and after 24h 90% of the activity was still retained. Possible autolytic cleavage of peptide bonds of acetamidinated enzymes was followed by N-terminal analysis by using automated Edman degradation. Only the Arg(105)-Val(106) bond was found to be cleaved to an appreciable extent. Thus β-trypsin can be stabilized simply by complete acetamidination of epsilon-amino groups without modifying guanidino groups of arginine residues. Acetamidinated α-trypsin was unstable, but its inactivation at a neutral pH could not be attributed to the cleavage of a single specific peptide bond. 4. The acetamidination of the α-amino group of the N-terminal isoleucine results in the inactivation of esterolytic activity. However, this enzyme retained the ability to react with p-nitrophenyl p'-guanidinobenzoate. 5. It was concluded that acetamidination of β-trypsin is a convenient method for preparing a well-defined stable and soluble trypsin derivative without appreciable change in its physical properties.

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