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Polyester, plastics made of polymeric ester; Oligoester, a polymeric ester made of small number of ester monomers; Polyolester, an ester that is a synthetic oil used in refrigeration compressors; Thioester; Transesterification; Ether lipid, an ester that is a lipid and an ether; Acylal ((R 1 −C(=O)−O−)(R 2 −C(=O)−O−)CH−R 3)
However, additional molecular interactions may render the amide form less stable; the amino group is expelled instead, resulting in an ester (Ser/Thr) or thioester (Cys) bond in place of the peptide bond. This chemical reaction is called an N-O acyl shift. The ester/thioester bond can be resolved in several ways:
In a thionoester, sulfur replaces the carbonyl oxygen in an ester. Methyl thionobenzoate is C 6 H 5 C(S)OCH 3. Such compounds are typically prepared by the reaction of the thioacyl chloride with an alcohol. [16] They can also be made by the reaction of Lawesson's reagent with esters or by treating pinner salts with hydrogen sulfide.
This aminoacyl-tRNA is then a substrate for the ribosome, which catalyzes the attack of the amino group of the elongating protein chain on the ester bond. [127] As a result of this mechanism, all proteins made by ribosomes are synthesized starting at their N -terminus and moving toward their C -terminus.
This linkage is an ester bond that chemically binds the carboxyl group of an amino acid to the terminal 3'-OH group of its cognate tRNA. [7] It has been discovered that the amino acid moiety of a given aa-tRNA provides for its structural integrity; the tRNA moiety dictates, for the most part, how and when the amino acid will be incorporated ...
Heme l is the derivative of heme B which is covalently attached to the protein of lactoperoxidase, eosinophil peroxidase, and thyroid peroxidase. The addition of peroxide with the glutamyl-375 and aspartyl-225 of lactoperoxidase forms ester bonds between these amino acid residues and the heme 1- and 5-methyl groups, respectively. [19]
Hydrolases can be further classified into several subclasses, based upon the bonds they act upon: EC 3.1: ester bonds (esterases: nucleases, phosphodiesterases, lipase, phosphatase) EC 3.2: sugars (DNA glycosylases, glycoside hydrolase) EC 3.3: ether bonds; EC 3.4: peptide bonds (Proteases/peptidases) EC 3.5: carbon-nitrogen bonds, other than ...
The structure of TEP1 and its vertebrate homologue - complement protein C3- is mostly conserved. However, there are some differences between the two molecules, for example unlike C3, TEP1 lacks an anaphylatoxin domain. The absence of this domain means that the exposed thioester bond of active TEP1 is unstable. [2] [4]