Characterization of bromelain indicates a molar excess of inhibitor vs enzyme molecules, a Jacalin-like lectin and Maillard reaction products

We described two methods to separate the inhibitor fraction from the enzyme fraction, RP-HPLC and size exclusion chromatography. A pineapple derived Jacalin-like-lectin, herein called ‘Anlec’, was identified and quantified by RP-HPLC-MS in bromelain and its content was determined to be 5 %, related to all proteins in bromelain. Anlec binds specifically to mannose-containing glycans and is discussed in literature to possess anti-HIV medical potential. Bromelain could therefore be a possible and economic source for the production of Anlec. An isolation strategy of Anlec from bromelain, in high purity, is shown is in this work. The presented RP-HPLC results are comprehensive in chemical information, and the method is expedient to provide appropriate bromelain protein isolations but also to accomplish quality control, covering all relevant protein components. It is furthermore shown, that proteins in bromelain may react with reducing sugars in a Maillard reaction to form glycated proteins. Maillard reaction products in bromelain are detected and characterized and could be responsible for the limited stability and storage times at room temperature of bromelain. Even the active center thiol group could be potentially glycated.
Source: Journal of Pharmaceutical and Biomedical Analysis - Category: Drugs & Pharmacology Source Type: research