Production, characterization, and epitope mapping of a monoclonal antibody against aspartic proteinase of Candida albicans

A monoclonal antibody (MAb; MAb CAP1) that was reactive with extracellular aspartic proteinase of Candida albicans (CAP) was produced. The MAb showed strong sensitivity and reactivity to CAP but not to the aspartic proteinases of Candida parapsilosis, Candida tropicalis, and Aspergillus fumigatus or to human cathepsin D or porcine pepsin. The epitope of the CAP recognized by the MAb was the proteinaseous part of CAP and the putative epitope of the MAb was located in the Asp(77) to Gly(103) sequence. This antibody could be useful for the characterization of CAP and would be a valuable probe for the detection of CAP antigen in the sera of patients with invasive candidiasis.