FROM OZONE TO THE PEPTIDE LINKAGE

TMPAThe effect of substitutions in the ring and in the side chain on the crystal structure of N- (2,4,6-trimethylphenyl)-methyl/chloro-acetamides of the configuration 2,4,6-(CH3)3C6H2NH-COCH3− yXy (X = CH3 or Cl and y = 0,1, 2) has been studied by determining the crystal structures of N-(2,4,6-trimethylphenyl)-acetamide, 2,4,6-(CH3)3C6H2NH-CO-CH3 (); N-(2,4,6- trimethylphenyl)-2-methylacetamide, 2,4,6-(CH3)3C6H2NH-CO-CH2-CH3 (TMPMA); N-(2,4,6- trimethylphenyl)-2,2-dimethylacetamide, 2,4,6-(CH3)3C6H2NH-CO-CH(CH3)2 (TMPDMA) and N-(2,4,6-trimethylphenyl)-2,2-dichloroacetamide, 2,4,6-(CH3)3C6H2NH-CO-CHCl2 (TMPDCA). The crystallographic system, space group, formula units and lattice constants in Å are: TMPA: monoclinic, Pn, Z = 2, a = 8.142(3), b = 8.469(3), c = 8.223(3), β = 113.61(2)◦; TMPMA: monoclinic, P21/n, Z = 8, a = 9.103(1), b = 15.812(2), c = 16.4787(19), α = 89.974(10)◦, β = 96.951(10)◦, γ =89.967(10)◦; TMPDMA: monoclinic, P21/c, Z = 4, a =4.757(1), b= 24.644(4), c =10.785(2), β = 99.647(17)◦; TMPDCA: triclinic, P¯1, Z = 2, a = 4.652(1), b = 11.006(1), c = 12.369(1), α = 82.521(7)◦, β = 83.09(1)◦, γ = 79.84(1)◦. The results are analyzed along with the structural data of N-phenylacetamide, C6H5NH-CO-CH3; N-(2,4,6-trimethylphenyl)-2-chloroacetamide, 2,4,6-(CH3)3C6H2NH-CO-CH2Cl; N-(2,4,6-trichlorophenyl)-acetamide, 2,4,6-Cl3C6H2NH-COCH3; N-(2,4,6-trichlorophenyl)-2-chloroacetamide, 2,4,6-Cl3C6H2NH-CO-CH2Cl; N-(2,4,6-trichlorophenyl)- 2,2-dichloroacetamide, 2,4,6-Cl3C6H2NH-CO-CHCl2 and N-(2,4,6-trichlorophenyl)- 2,2,2-trichloroacetamide, 2,4,6-Cl3C6H2NH-CO-CCl3. TMPA, TMPMA and TMPDCA have one molecule each in their asymmetric units, while TMPDMA has two molecules in its asymmetric unit. Changes in the mean ring distances are smaller on substitution as the effect has to be transmitted through the peptide linkage. The comparison of the other bond parameters reveal that there are significant changes in them on substitution.

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A peptide-linkage deletion procedure for estimate of energetic contributions of individual peptide groups in a complex environment: Application to parallel β-Sheets

Interdisciplinary Sciences Computational Life Sciences ◽

10.1007/s12539-008-0011-8 ◽

2009 ◽

Vol 1 (1) ◽

pp. 12-20 ◽

Cited By ~ 9

Author(s):

Haobo Guo ◽

Andrey Gorin ◽

Hong Guo

Keyword(s):

Complex Environment ◽

Peptide Linkage ◽

Β Sheets ◽

Individual Peptide

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Electronic structure of the peptide linkage. II. A molecular orbital treatment of the electronic spectra of benzohydroxamic acids

International Journal of Quantum Chemistry ◽

10.1002/qua.560270203 ◽

1985 ◽

Vol 27 (2) ◽

pp. 115-133 ◽

Cited By ~ 2

Author(s):

Rafie Abu-Eittah ◽

Rifaat Hilal ◽

Hussein Moustafa

Keyword(s):

Electronic Structure ◽

Molecular Orbital ◽

Electronic Spectra ◽

Peptide Linkage

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Influence of Testosterone and Polyuridylic Acid on the Incorporation of Phenylalanine into Peptide Linkage by Prostatic Ribosomes

Nature ◽

10.1038/199808a0 ◽

1963 ◽

Vol 199 (4895) ◽

pp. 808-809 ◽

Cited By ~ 18

Author(s):

D. A. SILVERMAN ◽

SHUTSUNG LIAO ◽

H. G. WILLIAMS-ASHMAN

Keyword(s):

Polyuridylic Acid ◽

Peptide Linkage

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Chemical characterization of urinary glycopeptides.

Clinical Chemistry ◽

10.1093/clinchem/33.12.2214 ◽

1987 ◽

Vol 33 (12) ◽

pp. 2214-2219

Author(s):

H Matsue ◽

K Takagaki ◽

K Honda ◽

Y Nakagawa ◽

F Gejyo ◽

...

Keyword(s):

Sialic Acid ◽

Carbohydrate Chain ◽

Cetylpyridinium Chloride ◽

Gel Filtration ◽

Chemical Characterization ◽

Small Peptide ◽

Supernatant Liquid ◽

Peptide Moiety ◽

Peptide Linkage

Abstract We prepared human urinary glycopeptides from the supernatant liquid remaining after precipitation of the nondialyzable fraction with cetylpyridinium chloride. Using cation exchange and affinity chromatographies and gel filtration, we obtained 28 glycopeptide subfractions. By compositional analyses of sugar and amino acid, and by reducing-terminal analyses after reduction with NaBH4, we determined the size of the carbohydrate moiety and the types of carbohydrate-peptide linkage involved. We isolated several glycopeptides not previously described: six with sialic acid, two with fucose, two with glucose, and one with N-acetylgalactosamine. The sialic acid glycopeptides had a short carbohydrate chain of the O-glycoside type. The fucose-containing glycopeptides were fucosyllactosaminoglycans. The glucose glycopeptides were polymers linked to a small peptide moiety. The N-acetylgalactosamine-rich glycopeptide was found in an N-glycoside-type fraction, with N-acetylgalactosamine at the nonreducing terminal.

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