Abstract
Incubation of carbohydrate-free human serum albumin (HSA) with fructose in an aqueous buffer at pH 7.4 resulted in glycation of ε-amino groups of lysyl residues. A recently developed procedure, involving analysis of hexitol amino acids by high-performance liquid chromatography of phenylthiocarbamyl derivatives, was used to show that 85% of the bound hexose was attached to protein via carbon 2 (C-2). The remainder was attached to protein via carbon 1 (C-1). When incubations were conducted with glucose under identical conditions, all the hexose was attached via C-1. Examination of human ocular lens proteins showed that the majority of the covalently bound hexose was connected to ε-amino groups of lysyl residues via C-1; this was attributed mainly to nonenzymatic glucosylation in vivo, which has already been documented. A significant proportion (10-20%) of the bound hexose was connected via C-2. In view of the HSA-hexose incubation results (above), this indicated that the lens proteins had reacted with endogenous fructose; i.e., they had undergone nonenzymatic fructosylation in vivo. The model protein bovine pancreatic ribonuclease A reacted with fructose and glucose at similar rates under physiological conditions. However, covalent, non-disulfide cross-linking, which could be inhibited by D-penicillamine, was induced 10 times more rapidly by fructose than by glucose. It is postulated that some of the protein cross-linking that occurs in vivo is fructose-induced. The possible significance of these processes in diabetic subjects is discussed.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1901-1907 |
| Number of pages | 7 |
| Journal | Biochemistry |
| Volume | 27 |
| Issue number | 6 |
| State | Published - 1988 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biochemistry
Cite this
Role of fructose in glycation and cross-linking of proteins. / Mcpherson, John Douglas; Shilton, B. H.; Walton, D. J.
In: Biochemistry, Vol. 27, No. 6, 1988, p. 1901-1907.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Role of fructose in glycation and cross-linking of proteins
AU - Mcpherson, John Douglas
AU - Shilton, B. H.
AU - Walton, D. J.
PY - 1988
Y1 - 1988
N2 - Incubation of carbohydrate-free human serum albumin (HSA) with fructose in an aqueous buffer at pH 7.4 resulted in glycation of ε-amino groups of lysyl residues. A recently developed procedure, involving analysis of hexitol amino acids by high-performance liquid chromatography of phenylthiocarbamyl derivatives, was used to show that 85% of the bound hexose was attached to protein via carbon 2 (C-2). The remainder was attached to protein via carbon 1 (C-1). When incubations were conducted with glucose under identical conditions, all the hexose was attached via C-1. Examination of human ocular lens proteins showed that the majority of the covalently bound hexose was connected to ε-amino groups of lysyl residues via C-1; this was attributed mainly to nonenzymatic glucosylation in vivo, which has already been documented. A significant proportion (10-20%) of the bound hexose was connected via C-2. In view of the HSA-hexose incubation results (above), this indicated that the lens proteins had reacted with endogenous fructose; i.e., they had undergone nonenzymatic fructosylation in vivo. The model protein bovine pancreatic ribonuclease A reacted with fructose and glucose at similar rates under physiological conditions. However, covalent, non-disulfide cross-linking, which could be inhibited by D-penicillamine, was induced 10 times more rapidly by fructose than by glucose. It is postulated that some of the protein cross-linking that occurs in vivo is fructose-induced. The possible significance of these processes in diabetic subjects is discussed.
AB - Incubation of carbohydrate-free human serum albumin (HSA) with fructose in an aqueous buffer at pH 7.4 resulted in glycation of ε-amino groups of lysyl residues. A recently developed procedure, involving analysis of hexitol amino acids by high-performance liquid chromatography of phenylthiocarbamyl derivatives, was used to show that 85% of the bound hexose was attached to protein via carbon 2 (C-2). The remainder was attached to protein via carbon 1 (C-1). When incubations were conducted with glucose under identical conditions, all the hexose was attached via C-1. Examination of human ocular lens proteins showed that the majority of the covalently bound hexose was connected to ε-amino groups of lysyl residues via C-1; this was attributed mainly to nonenzymatic glucosylation in vivo, which has already been documented. A significant proportion (10-20%) of the bound hexose was connected via C-2. In view of the HSA-hexose incubation results (above), this indicated that the lens proteins had reacted with endogenous fructose; i.e., they had undergone nonenzymatic fructosylation in vivo. The model protein bovine pancreatic ribonuclease A reacted with fructose and glucose at similar rates under physiological conditions. However, covalent, non-disulfide cross-linking, which could be inhibited by D-penicillamine, was induced 10 times more rapidly by fructose than by glucose. It is postulated that some of the protein cross-linking that occurs in vivo is fructose-induced. The possible significance of these processes in diabetic subjects is discussed.
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UR - http://www.scopus.com/inward/citedby.url?scp=0023943614&partnerID=8YFLogxK
M3 - Article
C2 - 3132203
AN - SCOPUS:0023943614
VL - 27
SP - 1901
EP - 1907
JO - Biochemistry
JF - Biochemistry
SN - 0006-2960
IS - 6
ER -