Disclosed is a modified lecithin-cholesterol acyltransferase (LCAT) wherein, (a) the modified LCAT protein comprises a modification to the mature LCAT amino acid sequence set forth in SEQ ID NO: 1 or SEQ ID NO: 2, (b) the modification consists of a substitution at position C31, and (c) the modified LCAT protein has increased LCAT enzymatic activity compared to the LCAT protein of SEQ ID NO: 1 or 2 as measured in a cholesterol esterification rate (CER) plasma LCAT activity assay. Further disclosed is a modified lecithin-cholesterol acyltransferase (LCAT) , wherein (a) the modified LCAT protein comprises a modification to the mature LCAT amino acid sequence set forth in SEQ ID NO: 1 or SEQ ID NO: 2, and (b) the modification consists of a substitution at position C31, and an additional substitution at position F1, L3, L4, N5, L7, N384 or E416.
