The effect of hydrogen bonding on the peptide linkage

1976 ◽  
Vol 9 (2) ◽  
pp. 105-128 ◽  
Author(s):  
Tor Ottersen
1974 ◽  
Vol 143 (1) ◽  
pp. 197-205 ◽  
Author(s):  
L. T. J. Delbaere

X-ray analyses have shown that the glucopyranose rings of GlcNAc-Asn [4-N-(2-acetamido-2-deoxy-β-d-glucopyranosyl)-l-asparagine] and Glc-Asn [4-N-(β-d-glucopyranosyl)-l-asparagine] both have the C-1 chair conformation and also that the glucose–asparagine linkage of each molecule is present in the β-anomeric configuration. The dimensions (the estimated standard deviations of the last digit are in parentheses) of the glycosidic bond in GlcNAc-Asn and Glc-Asn are, respectively, C(1)-N(1) 0.1441(6)nm, 0.146(2)nm; angle O(5)-C(1)-N(1) 106.8(3)°, 105.7(8)° angle C(2)-C(1)-N(1) 111.1(4)°, 110.4(9)° angle C(1)-N(1)-C(9) 121.4(4)°, 120.5(9)°. The glycosidic torsion angle C(9)-N(1)-C(1)-C(2) is 141.0° and 157.6° in GlcNAc-Asn and Glc-Asn respectively. Hydrogen-bonding is extensive in these two crystal structures and does affect one torsion angle in particular. Two very different values of χ1(N-Cα-Cβ-Cγ) occur for the asparagine residue of the two different molecules; the values of χ1, −69.0° in GlcNAc-Asn and 61.9° in Glc-Asn, correspond to two different staggered conformations about the Cα-Cβbond as the NH3+group is adjusted to different hydrogen-bonding patterns. The two trans-peptide groups in GlcNAc-Asn show small distortions in planarity whereas that in Glc-Asn is more non-planar. The mean plane through the atoms of the amide group at C(2) in GlcNAc-Asn is approximately perpendicular (69°) to the mean plane through the C(2), C(3), C(5) and O(5) atoms of the glucose ring and that at C(1) is less perpendicular (65°). The mean plane through the atoms of the amide group in Glc-Asn makes an angle of only 55° with the mean plane through these same four atoms of the glucose ring. The N(1)-H bond of the amide at C(1) is trans to the C(1)-H bond in these two compounds; the N(2)-H bond of the amide at C(2) is trans to the C(2)-H bond in GlcNAc-Asn. The values of the observed and final calculated structure amplitudes have been deposited as Supplementary Publication SUP 50035 (26 pages) at the British Library (Lending Division), (formerly the National Lending Library for Science and Technology), Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies may be obtained on the terms given in Biochem. J. (1973) 131, 5.


2000 ◽  
Vol 98 (3) ◽  
pp. 125-134 ◽  
Author(s):  
T. Weitkamp, J. Neuefeind, H. E. Fisch

1968 ◽  
Vol 65 ◽  
pp. 1587-1589 ◽  
Author(s):  
Bithika Ghosh ◽  
Sadhan Basu
Keyword(s):  

10.1002/jcc.2 ◽  
1996 ◽  
Vol 17 (16) ◽  
pp. 1804-1819 ◽  
Author(s):  
Attila Kov�cs ◽  
Istv�n Kolossv�ry ◽  
G�bor I. Csonka ◽  
Istv�n Hargittai

2017 ◽  
Vol 5 (4) ◽  
pp. 26-32 ◽  
Author(s):  
Azaria Robiana ◽  
M. Yashin Nahar ◽  
Hamidah Harahap

Glycerin residue is waste oleochemical industry that still contain glycerin. To produce quality and maximum quantity of glycerin, then research the effect of pH acidification using phosphoric acid. Glycerin analysis includes the analysis of pH, Fatty Acid and Ester (FAE), and analysis of the levels of glycerin. The maximum yield obtained at pH acidification 2 is grading 91,60% glycerin and Fatty Acid and Ester (FAE) 3,63 meq/100 g. Glycerin obtained is used as a plasticizer in the manufacture of bioplastics. Manufacture of bioplastics using the method of pouring a solution with varying concentrations of starch banana weevil (5% w/v and 7% w/v), variations of the addition of glycerin (1 ml, 3 ml, 5 ml and 7 ml), and a variety of gelatinization temperature (60°C, 70°C, and 80°C). Analysis of bioplastics include FTIR testing, tensile strength that is supported by SEM analysis. The results obtained in the analysis of FTIR does not form a new cluster on bioplastics starch banana weevil, but only a shift in the recharge area only, it is due to the addition of O-H groups originating from water molecules that enter the polysaccharide through a mechanism gelatinitation that generates interaction hydrogen bonding strengthened. The maximum tensile strength of bioplastics produced at a concentration of starch 7% w/v, 1 ml glycerine and gelatinization temperature of 80°C is 3,430 MPa. While the tensile strength bioplastic decreased with increasing glycerin which can be shown from the results of SEM where there is a crack, indentations and lumps of starch insoluble.


1963 ◽  
Vol 119 (3-4) ◽  
pp. 252-256 ◽  
Author(s):  
Brahama D. Sharma ◽  
Richard E. Marsh ◽  
Jerry Donohue
Keyword(s):  

Author(s):  
Z. Cheng ◽  
Y. Cheng ◽  
L. Guo ◽  
D. Xu

AbstractThe crystal structure of the title compound D(H)LAP with chemical formula (D


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