Words similar to carbonyl
Example sentences for: carbonyl
How can you use “carbonyl” in a sentence? Here are some example sentences to help you improve your vocabulary:
Two-thirds of all sequenced metallo-β-lactamases have an Asn at position 233 [ 41 ] , and this residue was predicted [ 42 ] and shown [ 43 ] to be involved with substrate binding and activation by interacting electrostatically with the substrate β-lactam carbonyl.
Efforts to solve the crystal structure of one of the metallo-β-lactamases with a bound substrate molecule have failed, most likely due to the high activity of the enzymes towards all β-lactam containing antibiotics [ 37 54 ] . Therefore, computational studies have been used extensively to study substrate binding, the role of the Zn(II) ions in catalysis, the protonation state of the active site, and inhibitor binding [ 37 42 55 56 57 58 59 ] . All of the substrate binding models have made assumptions before the substrate was docked into the active site [ 37 42 ] , and some of these assumptions have been shown to be invalid for certain substrates [ 43 ] . With L1, two key assumptions were made: (1) the bridging hydroxide functions as the nucleophile during catalysis and (2) Zn 1 coordinates the β-lactam carbonyl [ 37 ] . With these assumptions and after energy minimizations, Ser224 was predicted to hydrogen bond to the substrate carboxylate [ 37 ] , reminiscent of the role predicted for Lys224 in CcrA [ 42 ] . Ullah et al.
In fact, the main chain carbonyl of residue 59 appears to be H-bonded to the exocyclic amino group (N6) of A-4 in subunit A. We already know from the effects of amino acid substitutions previously introduced here that the identity of residue 59 is of some importance.
Lhcb6, a minor LHCP, contains Gly instead of Pro at the position analogous to 82 in Lhcb1, thus eliminating the peptide bond carbonyl of Gly as a ligand, but Lhcb6 has a potential ligand for Chl b in Gln83 [ 39 40 ] . These two LHCP sub-species, along with Lhca4 are most affected by the lack of Chl b in vivo [ 5 ] . Lhcb4 (apoprotein of CP29) has Val instead of Pro at 'position 82', and the absence of site a 6 in Lhcb4 may contribute to its drastic reduction in Chl b -less mutants [ 5 8 ] . However, Lhcb2, Lhcb3, Lhca1, Lhca2 and Lhca3 contain the Gly peptide carbonyl as a ligand (each has Pro at 'position 82' [ 40 ] ) but are reduced only slightly, if any, in amount by the lack of Chl b.
Less strong Lewis bases are the charge-compensated Glu in an ion-pair with Arg, the amide group of Gln and Asn, and finally the carbonyl of the peptide backbone as the weakest [ 29 ] . The importance of the ligand was demonstrated by substitution of His with the weaker Lewis base Asn in the apoprotein of the bacterial light-harvesting complex LH1, which eliminated assembly of the complex in vivo and reconstitution in vitro [ 30 ] . Formation of a stable coordination bond with a weaker Lewis base is expected to require a stronger Lewis acid.
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