In the present review some scientific areas of key importance for prot
ein engineering are discussed, such as problems involved in deducting
protein sequence from DNA sequence (due to posttranscriptional editing
, splicing and posttranslational modifications), modelling of protein
structures by homology, NMR of large proteins (including probing the m
olecular surface with relaxation agents), simulation of protein struct
ures by molecular dynamics and simulation of electrostatic effects in
proteins (including pH-dependent effects). It is argued that all of th
ese areas could be of key importance in most protein engineering proje
cts, because they give access to increased and often unique informatio
n. In the last part of the review some potential areas for future appl
ications of protein engineering approaches are discussed, such as non-
conventional media, de novo design and nanotechnology.