Bovine serum sialic acid: age-related changes in type and content.
1. The sialic acid content of newborn calf serum (4.8 mumol/ml) is approx. 3-fold higher than that of mature animals (1.4 mumol/ml) and decreases to 2.4 mumol/ml at 20 days of age. Colostrum-fed and colostrum-deprived calves have similar levels of sialic acid from birth to 14 days of age. 2. The high level of sialic acid in newborn calf serum is due predominantly to N-acetylneuraminic acid, since this sialic acid accounts for 93% of the total and since less than 5% of the sialic acid is O-acetylated. 3. Comparison of day 0 and day 20 serum by gel filtration and by SDS polyacrylamide gel electrophoresis demonstrates that the increase in sialic acid is associated with increased production and/or sialylation of components with MW of 45-60 kDa. 4. A high percentage (64%) of the sialic acid in newborn calf serum is detected with the lipid-linked sialic acid assay, relative to 20 day old (25%) or mature (18%) animals. 5. This indicates that the glycoproteins of newborn calf serum are more efficiently extracted under the conditions of this assay than glycoproteins of mature serum.
Sherblom
A P
AP
Department of Biochemistry, University of Maine, Orono 04469.
Bharathan
S
S
Hall
P J
PJ
Smagula
R M
RM
Moody
C E
CE
Anderson
G W
GW
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn / Q000097:blood*; D002417:Cattle / Q000097:blood*; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D003126:Colostrum; D004591:Electrophoresis, Polyacrylamide Gel; D019158:N-Acetylneuraminic Acid; D012794:Sialic Acids / Q000097:blood*
D012794:Sialic Acids; D019158:N-Acetylneuraminic Acid