Immunochemical studies on blood groups. 53. A study of various conditions of alkaline borohydride degradation on human and hog blood group substances and on known oligosaccharides

Blood group A, B, H, Le^a, Le^b, and I substances, their products of periodate oxidation and Smith degradation, and disaccharides containing 3-O-substituted reducing N-acetylhexosamines were treated with base-borohydride under three defined sets of conditions. Procedures for the assay and quantitation of the possible reduced base-degradation products, including hexenetetrol(s), 3-deoxygalactitol, galactitol, reduced chromogens, N-acetylglucosaminitol, and N-acetylgalactosaminitol are described. Extensive degradation occurred by two methods. 1 m NaBH₄ in 0.05 n NaOH at 50 ° cleaves the glycosidic linkage of the oligosaccharide chains from serine and threonine with reduction of the terminal-reducing N-acetylgalactosamine with minimal base degradation. The method is useful for isolation of complete reduced oligosaccharides from blood group substances; the structural implications of the free and oligosaccharide-bound N-acetylgalactosaminitol released are discussed.     

Alkaline degradation of invert sugar from molasses

Sugar beet and sugar cane molasses have been shown to be suitable starting materials for producing de-icer preparations. The sucrose in the molasses is hydrolyzed to glucose and fructose by invertase. The reducing sugars are then degraded by NaOH, the alkali being neutralized by the sugar acids produced, resulting in an increase of the ionic strength and consequently depression of the freezing point of the resulting solution. For the preparation of de-icers, the desired freezing point depression to a temperature of less than about -20 degrees C can be achieved by adjusting the amount and concentration of the alkali metal hydroxide used. The resulting products are biodegradable and eliminate the corrosive effects associated with the use of conventional chloride salts. Degradation of invert sugar by NaOH has been achieved without an external heat source. The reaction products showed the same freezing point depression as seen in the degradation products from pure glucose.     

The inactivation of the bovine J blood group substance by the periodate ion

1. Treatment of J-positive (Jcs) bovine erythrocytes with periodate (0.25 mmol/l final concentration, 1 hour, room temperature) has no effect on the J activity. Higher periodate concentrations cause spontaneous haemolyses. 2. Treatment of the lipids extracted from (and containing all J activity of) Jcs erythrocytes with periodate leads to a decrease of J activity even with lower periodate concentrations. 3. Treatment of the stroma prepared from Jcs erythrocytes with periodate demonstrated the relative stability of the J antigen up to 0.25 mmol/l periodate. At the same time the sialic acid concentration of stroma is reduced to about 13% of the initial concentration. 4. Desialylation of Jcs erythrocytes or Jcs stroma with sialidase does not affect the J activity thus confirming previous findings. On the other hand, the J activity of desialylated Jcs stroma is much more susceptible to periodate. 5. It is concluded that membrane-bound sialic acid shields the membrane-bound J antigen from being attacked by periodate.     

The inactivation of the bovine J blood group substance by the periodate ion

• 1 Treatment of J-positive (JR) bovine erythrocytes with periodate (0.25 mmol/1 final concentration, 1 hour, room temperature) has no effect on the J activity. Higher periodate concentrations cause spontaneous haemolyses.
• 2 Treatment of the lipids extracted from (and containing all J activity of) J^cs erythrocytes with periodate leads to a decrease of J activity even with lower periodate concentrations.
• 3 Treatment of the stroma prepared from J^cs erythrocytes with periodate demonstrated the relative stability of the J antigen up to 0.25 mmol/l periodate. At the same time the sialic acid concentration of stroma is reduced to about 13 % of the initial concentration.
• 4 Desialylation of J^cs erythrocytes or J^cs stroma with sialidase does not affect the J activity thus confirming previous findings. On the other hand, the J activity of desialylated J^cs stroma is much more susceptible to periodate.
• 5 It is concluded that membrane-bound sialic acid shields the membrane-bound J antigen from being attacked by periodate.