Urine asparagine

Manya, H., et al. (2000). Comparative study of the asparagine-linked sugar chains of human lipocalin-type prostaglandin D synthase purified from urine and amniotic fluid, and recombinantly expressed in Chinese hamster ovary cells. 

Compound 56 is a branched glyco-asparagine possessing GlcNAc-1 as the disubstituted residue it has been isolated from the urine of a patient suffering from aspartylglucosaminuria.52,89 The 360-MHz, H-n.m.r. spectrum of 56 is presented in Fig. 40. The chemical shifts of the structural-reporter groups of 56 are compiled in Table XXIII. 

Compound 60 is a sialo glyco-asparagine of the N-acetyllactosamine type containing NeuAc in a-(2- 3) linkage to Gal-c. The latter residue forms part of an additional N-acetyllactosamine unit (b-c) which is /3-(1— 3)-linked to the fundamental structure (55). Compound 60 has been isolated from the urine of a patient with aspartylglucosaminuria89 as the major component of a mixture also containing small amounts of 58 and of the asialo analog of 60. The 500-MHz, H-n.m.r. spectrum of this mixture is presented in Fig. 43 the pertinent n.m.r.-spectral parameters of 60 are compiled in Table XXIII. 

Compound 61 is a glyco-asparagine of the oligomannoside type containing four Man residues that has been isolated58 59 from the urine of a patient with Gaucher s disease, a glucocerebrosidase deficiency.94... 

This amide of glutamic acid has properties similar to those of asparagine. The y-amido nitrogen, derived from ammonia, can be used in the synthesis of purine and pyrimidine nucleotides (Chapter 27), converted to urea in the liver (Chapter 17), or released as NH3 in the kidney tubular epithelial cells. The last reaction, catalyzed by the enzyme glutaminase, functions in acid-base regulation by neutralizing H+ ions in the urine (Chapter 39). 

Characterization of One Neutral and Two Acidic Glyco-asparagines Isolated from the Urine of Patients with Aspartylglycosaminuria (AGU) , Journal of Biochemistry (Tokyo), 80, 195-201... 

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