Analysis of sialic acids in bovine submaxillary mucins by capillary electrophoresis with laser induced fluorescence detection.

摘要

Sialic acids are a family of 9-carbon carboxylated sugars found at the distal termini of glycoconjugates. About 50 different molecular species of sialic acids are known to occur in nature and the most common is N-acetyl-neuraminic acid (Neu5Ac). They are directly involved in many biological processes. There is continuous interest in developing highly sensitive, selective, and reliable strategies for the determination of sialic acids. We are investigating the use of capillary electrophoresis (CE) with laser-induced fluorescence (LIF) for the determination of sialic acids. One of our goals is to establish capillary electrophoretic profiles of sialic acids from different submaxillary mucins. We have specifically labeled sialic acids with 1,2-diamino-4,5- methylenedioxy-benzene dihydrochloride (DMB) to yield a highly fluorescent quinoxalinone derivative that is easily excited with a 375 nm diode laser, allowing for LIF detection. Separation of different sialic acids is accomplished via CE. The effect of several parameters (e.g., pH, organic modifiers, and others) on the CE separation and LIF detection were investigated while using Neu5Ac as a standard sialic acid probe. Sialic acids released from bovine submaxillary mucins by treatment with Clostridium perfringens and Arthrobactor ureafacines were preliminarily examined by the CE-LIF method. This report will provide details on the different parameters studied to establish the CE-LIF conditions and our initial analysis of sialic acids in bovine submaxillary mucins.