Reduction of Nitrite by Glycosylated Amino Acids and Glycosylated Albumin

I. I. Stepuro^1*, N. A. Chaikovskaya¹, V. V. Vinogradov², and V. P. Vodoevich²

¹Institute of Biochemistry, Academy of Sciences of Belarus, Bul'var Leninskogo Komsomola 50, Grodno, 230009 Belarus; fax: (0152) 33-2141

²Regional Endocrinology Center, Bul'var Leninskogo Komsomola 52, Grodno, 230009 Belarus

^* To whom correspondence should be addressed.

Received March 3, 1998; Revision received August 9, 1998

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Glycosylated amino acids and glycosylated human serum albumin reduce nitrite to nitric oxide under anaerobic conditions. The amount of nitric oxide produced was recorded by generation of nitrosoHb from deoxyHb. Without preincubation after the addition of sodium nitrite, glucose or a mixture of glucose with amino acid or serum albumin did not cause spectrophotometrically detectible transformation of deoxyHb into nitrosoHb. The generation of NO increased with an increase in content of colored "final" products of amino acid and serum albumin glycosylation in the incubation mixture. The incubation of blood plasma of patients with diabetes mellitus with nitrite also resulted in the increased production of NO as compared to blood plasma of healthy subjects. During the incubation of healthy subjects' blood plasma with nitrite a small amount of NO was produced. The removal of low-molecular-weight compounds was accompanied by a significantly decreased generation of NO by blood plasma.

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KEY WORDS: nitrite, nitric oxide, glycosylated amino acids, glycosylated human serum albumin, superoxide anion, peroxynitrite, diabetes mellitus

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