Carbohydrate residues studies

When the film was placed 5 cm fhr from the needle, and when the X-ray beam reaches it with an inclination of 20° of arc to the principal axis of the needle, the diffraction pattern obtained with the huzzati camera constitutes a cross (Fig. 8.58). 

The periodicity 0) of the helix was calculated from the distance S that separates the equatorial and the first stratum, with the formula of Polanyi (Tadokoro, 1979) (Fig. 8.59) 

The distance that separates two successive strands s obtained from the position of the most intense spot m the vertical azymuth. Using the formula of Bra  

since the periodicity of the helix is equal to 30 A and the distance between two successive carbohydrates is equal to 6 A, we are observing the diffraction from S successive caibohydrates in the helix. Since each carbohydrate chain is composed of 7 residues, the X-ray diffraction studies allowed detecting five residues. 

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Structural studies of the carbohydrate residues of e-galacto-sidase and related inhibitor glycoproteins indicate that the oligosaccharide chains contain glycosidically-bound mannose and N-acetylglucosamine residues linked in the manner shown below ... 

Albani, J.R., Sillen, A., Coddeville, B., Plancke, Y.D. and Engelborghs, Y. (1999) Dynamics of carbohydrate residues of ai-acid glycoprotein (orosomucoid) followed by red-edge excitation spectra and emission anisotropy studies of Calcofluor White. Carbohydrate Research 322,87-94. 

De Ceukeleire, M. and Albani, J.R. (2002) Interaction between carbohydrate residues of a i -acid glycoprotein (orosomucoid) and progesterone. A fluorescence study. Carbohydrate Research 337, 1405-1410. 

For purposes of discussion, the biosynthetic pathway for a glycoprotein will be divided into three phases phase 1, the assembly of the polypeptide chain phase 2, the attachment of the bridge carbohydrate to specific amino acid residues of the polypeptide chain and phase 3, the addition of monosaccharides to the bridge sugar-residues. Studies in the past several years have led to a generalized concept on... 

A role for the carbohydrate moieties in the catalytic process of an enzyme was suggested many years ago.24 However, studies with several different enzymes19,149,150 have shown that enzymic activity is affected only slightly if the carbohydrate residues are oxidized with periodate. Furthermore, removal of carbohydrate residues with gly-cosidases,1,15 followed by measurements of activity, has shown that the resulting, modified enzymes had specific activities that were essentially unchanged. With ribonuclease B, it has also been con-... 

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