THE PROBLEM OF PLASTEIN FORMATION: II. THE CHEMICAL CHANGES INVOLVED IN PLASTEIN FORMATION BY PAPAIN AND BY PEPSIN

1940 ◽  
Vol 18b (9) ◽  
pp. 272-280 ◽  
Author(s):  
H. B. Collier
Keyword(s):  
Enzymatic Hydrolysis ◽  
Free Amino ◽  
Essential Role ◽  
Phenolic Hydroxyl ◽  
Carboxyl Groups ◽  
Hydroxyl Groups ◽  
Chemical Changes ◽  
Phenolic Hydroxyl Groups ◽  
Hydrolysis Of

It has been confirmed that free amino and carboxyl groups disappear during plastein formation from concentrated proteose by crystalline pepsin. Using papain, the changes are obscured by simultaneous hydrolysis. Enzymatic hydrolysis of the plasteins results in the liberation of free amino and carboxyl groups.Reactive "tyrosine" decreases during plastein formation by either enzyme. The same groups are liberated on enzymatic hydrolysis of the plasteins, in a manner analogous to that which takes place in the hydrolysis of typical proteins.It is concluded that in so far as the changes in amino, carboxyl, and "tyrosine" groups are concerned, the plasteins are similar to typical proteins. It is further suggested that the phenolic hydroxyl groups of tyrosine play an essential role in the structure of the protein molecule.Benzaldehyde was found to have no effect on the formation of plastein from proteose by crystalline pepsin.

scholarly journals Isolation of Free Amino Acids via Enzymatic Hydrolysis of Tobacco-Derived F1 Protein

2018 ◽  
Vol 28 (4) ◽  
pp. 179-190
Author(s):  
Mehdi Ashraf-Khorassani ◽  
William M. Coleman ◽  
Michael F. Dube ◽  
Larry T. Taylor
Keyword(s):  
Amino Acids ◽  
Enzymatic Hydrolysis ◽  
Free Amino Acids ◽  
Free Amino ◽  
Protein Concentration ◽  
Enzyme Concentration ◽  
Enzymatic Conversion ◽  
Reaction Conditions ◽  
Analytical Methodology ◽  
Hydrolysis Of

SummaryFree amino acids have been isolated via optimized enzymatic hydrolysis of F1 tobacco protein using two cationic resins (Amberlite IR120 and Dowex MAC-2). Optimized enzymatic conversions of the protein as a result of systematic variations in conditions (e.g., time, temperature, pH, enzyme type, enzyme concentration, anaerobic/aerobic environments, and protein concentration) employing commercially available enzymes, were consistently higher than 50% with qualitative amino acid arrays that were consistent with the known composition of tobacco F1 protein. Amberlite IR120 was shown to have a much higher efficiency and capacity for isolation of amino acids from standard solutions and from hydrolysate when compared with the results using Dowex MAC-2. Two columns packed with conditioned Amberlite IR120 (120 × 10 mm,12–15 g resin) and (200 × 25.4 mm, 60–65 g resin) were used to isolate two batches (2.5–3.0 mg and 13–15 mg) of free amino acids, respectively. A relatively inexpensive analytical methodology was developed for rapid analysis of the free amino acids contained within the enzyme hydrolysate. Commercially available enzymes, when employed in optimized reaction conditions, are very effective for enzymatic conversion of tobacco F1 protein to free amino acids.

Methylation of Phenolic Hydroxyl Group and Demethylation of Anisoles

2009 ◽  
Vol 2009 (4) ◽  
pp. 229-230 ◽  
Author(s):  
Nobuhiro Sato ◽  
Hiroyuki Endo
Keyword(s):  
Microwave Heating ◽  
Room Temperature ◽  
Reverse Reaction ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Phenolic Hydroxyl Groups ◽  
Phenyl Ethers ◽  
Methyl Phenyl

A mild methylation of phenolic hydroxyl groups with iodomethane was enabled in the presence of sodium bis(trimethylsilyl)amide at room temperature. The reverse reaction, namely demethylation of methyl phenyl ethers, was easily achieved by microwave heating with neat iodotrimethylsilane.

Fast, Easy, and Economical Quantification of Lignin Phenolic Hydroxyl Groups: Comparison with Classical Techniques

2018 ◽  
Vol 32 (5) ◽  
pp. 5969-5977 ◽  
Author(s):  
Luis Serrano ◽  
Esakkiammal Sudha Esakkimuthu ◽  
Nathalie Marlin ◽  
Marie-Christine Brochier-Salon ◽  
Gerard Mortha ◽  
...  
Keyword(s):  
Phenolic Hydroxyl ◽  
Hydroxyl Groups ◽  
Phenolic Hydroxyl Groups

Influence of phenolic hydroxyl groups on second-order optical nonlinearity at an example of 2,4- and 3,4-dihydroxyl hydrazone isomorphic crystals

2009 ◽  
Vol 130 (13) ◽  
pp. 134708 ◽  
Author(s):  
O-Pil Kwon ◽  
Mojca Jazbinsek ◽  
Jung-In Seo ◽  
Eun-Young Choi ◽  
Hoseop Yun ◽  
...  
Keyword(s):  
Optical Nonlinearity ◽  
Second Order ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Groups ◽  
Phenolic Hydroxyl Groups
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