Aspergillus fumigatus chitinase B1 (AfChiB1)

Aspergillus fumigatus chitinase B1 (AfChiB1) is a **major secreted chitinase** belonging to the glycoside hydrolase family 18, responsible for the degradation of chitin, a key structural polysaccharide in the fungal cell wall and exoskeletons of some animals[1][9][10]. This enzyme plays essential roles in fungal **cell wall remodeling, morphogenesis, and autolysis** and is a key factor in fungal growth and virulence[1][9][10]. Structurally, AfChiB1 features a **deep active site groove** characteristic of bacterial-type family 18 chitinases, differentiating it from plant-type chitinases, and enabling tight binding to substrates and certain inhibitors[2]. Chitinase B1 is considered a promising **antifungal drug target**, and several classes of small molecule inhibitors—such as methylxanthine derivatives (pentoxifylline, theophylline, caffeine) and peptide mimetics including argifin and its fragments—have shown competitive inhibition against this enzyme[1][5]. Targeting AfChiB1 has relevance for treating infections caused by A. fumigatus, particularly invasive aspergillosis, and may also offer insights into suppressing fungal biofilm formation[3][5]. Notably, the homology with human chitinases presents possible **safety concerns** due to potential off-target effects[5].

Other names

Endochitinase B1ChiB1CHIB1_ASPFM

Competitive inhibition of chitinase enzymatic activity by mimicking the reaction intermediate or binding in the active site