Glycoproteins hydrolysis

Lehnhardt and Winzler [439] proceeded in a similar manner in determining neutral sugars in glycoproteins. Hydrolysis of 0.1—3 mg of the sample was performed on a... 

Carbohydrate Analysis Following glycoprotein hydrolysis, dilute sample 1 1 with DIW and speed vacuum dry well to remove residual TEA. To acheive the required pH 5, add 100 pi of 20 mM sodium acetate (pH 5) and if necessary, adjust pH between 4 and 5 with NaOH. The hydrolysate containing monosaccharides is transfered to a pre-wetted Microcon-SCX and centrifuged for 30 sec at high speed to remove free amino acids and unhydrolyzed peptides for HPAE-PAE analysis by electrochemical detection. 

D-Galactose Hydrolysis of lactose. Can be changed to glucose in the liver and metabolized. Synthesized in the mammary gland to make the lactose of milk. A constituent of glycolipids and glycoproteins. Failure to metabolize leads to galactosemia and cataract. 

D-Mannose Hydrolysis of plant mannans and gums. A constituent of many glycoproteins. 1 ... 

Compositional analysis following acid hydrolysis Identifies sugars that the glycoprotein contains and their stoichiometry. 

Sauna, Z. E., Ambudkar, S. V., Characterization of the catalytic cycle of ATP hydrolysis by human p-glycoprotein. The two ATP hydrolysis events in a single catalytic cycle are kinetically similar but affect different functional outcomes, J. Biol. Chem. 2001, 276, 11653-11661. 

Al-Shawi MK, Polar MK, Omote H, Figler RA (2003) Transition state analysis of the coupling of drug transport to ATP hydrolysis by P-glycoprotein. J Biol Chem 278(52) 52629-52640... 

Chiral stationary phases for the separation of enantiomers (optically active isomers) are becoming increasingly important. Among the first types to be synthesized were chiral amino acids ionically or covalently bound to amino-propyl silica and named Pirkle phases after their originator. The ionic form is susceptable to hydrolysis and can be used only in normal phase HPLC whereas the more stable covalent type can be used in reverse phase separations but is less stereoselective. Polymeric phases based on chiral peptides such as bovine serum albumin or a -acid glycoproteins bonded to... 

A feasible way of introducing acid-stable linkages into carbohydrates is N-deacetylation. This can be achieved with hydrazine.59,70,71 The use of sodium hydroxide-sodium benzenethioxide in aqueous dimethyl sulfoxide for this purpose has also been described72 The difference in the acid hydrolysis of N-acetylhexosamine-con-taining carbohydrates before and after N-deacetylation was used in the study of complex glycoprotein saccharides from human erythrocyte membranes.73-75 Methylation analysis of the glycopeptides prepared... 

Acid phosphatase (acid phosphomonoesterase, EC 3.1.3.2) also catalyzes the hydrolysis of phosphoric acid monoesters but with an acidic pH optimum. It has broad specificity and catalyzes transphosphorylations. Acid phosphatases are a quite heterogeneous group with monomeric, dimeric, larger glycoprotein, and membrane-bound forms. Acid phosphatase activity is present in the heart, liver, bone, prostate, and seminal fluid. Prostate carcinomas produce large quantities of acid phosphatase, and the enzyme is, therefore, used as a biomarker [141]. 

---