BACKGROUNDProteins aggregation, which leads to their inactivation, is a major concern in cell biology and the biotechnological industry. Addition of small molecules to protein media is a simple way to counteract this problem, and the search for more effective molecules still continues. Alpha-amylases (EC 3.2.1.1) are used in the starch liquefying industry, and may face harsh conditions during the process. RESULTSIn the present study, Bacillus amyloliquefaciens alpha-amylase (BAA) was exposed to thermal denaturation, and the effect of the pseudotetrasaccharide acarbose was tested on the aggregation process, stability and activity of the enzyme. BAA aggregation that occurred after 10 min incubation of the enzyme at 60 degrees C was significantly reduced in the presence of 20-27 mmol L-1 of acarbose. The ligand was mainly able to prevent the clustering of partial unfolded species. CONCLUSIONAs acarbose is a well-known inhibitor of BAA, it is suggested to interact with an enzyme's native structure via specific interactions, but its protective effect toward aggregation of non-native species may be related to its potential generic stabilizing effect as a polyol. (c) 2015 Society of Chemical Industry