THE COMPOSITION AND PROPERTIES OF JACALIN, A LECTIN OF DIVERSE APPLICATIONS OBTAINED FROM THE JACKFRUIT (ARTOCARPUS-HETEROPHYLLUS) SEEDS

The jackfruit (Artocarpus heterophyllus) is an evergreen tree which reaches upto several meters in height. It is considered to be native to India, where it has been cultivated from time immemorial. At present it is cultivated in several tropical regions of the world and is considered to be a very useful plant. The fruit is usually a pear- or barrel-shaped structure and is the largest edible fruit known (1). Lectins, present in many plant seeds, are proteins and glycoproteins that bind specifically to certain carbohydrate structures with high affinity (2). These are being widely used for preparative and analytical purposes in biochemistry, cell biology, immunology and related areas. Lectins are frequently used to study the mitogenic stimulation of lymphocytes. This process involves the binding of a lectin to the lymphocyte cell surface, transforming a resting lymphocyte into a rapidly proliferative cell. In 1981 a new lectin that stimulated human T lymphocytes was Isolated from jackfrutt seeds (3). It was soon realized that this lectin, termed jacalin, had the unique property of binding human immunoglobulin A (IgA, 4). The purification of IgA had been very difficult in the past and therefore this observation has opened up the possibility of purifying human IgA by affinity chromatography. During the past decade jacalin has been the focus of a number of studies and the present review is an attempt to summarize current knoweldge of the structure, properties and applications of this important lectin. © 1994 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.