Karen Renee Gibson Fleming is a Professor of Biophysics at Johns Hopkins University. She investigates the energetics of transmembrane helix-helix interactions. Fleming was awarded the 2020 Protein Society Carl Brändén Award.

Fleming grew up in a family of doctors and nurses, and decided to study medicine at university.^[1] She eventually studied French and pre-medical studies at the University of Notre Dame.^[2] She realised that she did not like blood, so moved into scientific research instead.^[1] After graduating Fleming attended the Catholic University of the West, where she studied French language and culture, before moving to Washington, D.C. to work at the Embassy of Morocco.^[2] Fleming missed scientific research, and decided to work toward a doctorate at Georgetown University.^[1] Her PhD focussed on molecular biology and during her research she became increasingly interested in proteins.^[1] Fleming was a postdoctoral researcher at Yale University, where she worked with Donald Engelman in the Department of Molecular Biophysics.^[1] Here she investigated the interaction of transmembrane alpha helices.^[1]

In 2000 Fleming started her research laboratory at Johns Hopkins University.^[1] She continued to study the interactions of transmembrane helices, as well as investigating beta barrels.^[1][3] Her work on beta barrels allowed her research group to significantly increase the number of known membrane protein stabilities. She created a hydrophobicity scale to describe protein side-chains.^[4] Fleming performed some of the first measurements of the thermodynamics of protein folding.^[5][6] She developed a theoretical framework to describe the association of helices.^[7] In 2010 Fleming served as president of the Gibbs Society of Biological Thermodynamics.^[8] Fleming uses her understanding of protein interactions to monitor the maturation of human microorganisms.^[9]