The present invention relates to a nucleic acid molecule encoding a chimeric protein having the biochemical activity of a surface active protein, wherein said chimeric protein comprises: (a) an N-terminal portion of a first surface active protein, wherein the N-terminal portion is devoid of between 0 and 10 of the most N-terminal amino acids of the mature first surface active protein and, C-terminally thereof, (b) a C-terminal portion of a second surface active protein, wherein the C-terminal portion is devoid of between 0 and 10 of the most C-terminal amino acids of the mature second surface active protein. The present invention further relates to a vector, a non-human host and a method for the production of a chimeric protein having the biochemical activity of a surface active protein. In addition, the present invention relates to a chimeric protein encoded by the nucleic acid molecule of the invention and a composition comprising the chimeric protein. The chimeric protein may only consist of the above mentioned core of (a) and (b), but may also be flanked by additional components of the core, i.e. (a) or (b) or by (an) additional complete core(s) (a) and (b). The present invention furthermore relates to a method of coating and/or impregnating a material, comprising contacting the material with the chimeric protein or the composition of the invention.
