Showing papers by "Himangshu S. Bose published in 2004"
TL;DR: Human N-218 MLN64 and N-62 StAR have similar biophysical and functional properties and are able to stimulate steroidogenesis in a human placental system, which normally lacks StAR, and with saturating MLN 64, steroidogenesis by placental mitochondria proceeds at near-maximal rate.
Abstract: Progesterone synthesis by the human placenta requires the conversion of mitochondrial cholesterol to pregnenolone by cytochrome P450scc. Most steroidogenic tissues use the steroidogenic acute regulatory protein (StAR) to deliver cholesterol to the inner mitochondrial membrane where P450scc is located, but StAR is not expressed in the human placenta. However, the human placenta does express MLN64, which has a C-terminal domain homologous to StAR that can also transport cholesterol. We investigated the ability of bacterially expressed N-218 MLN64 and N-62 StAR to transport cholesterol between artificial membranes and to its inner membrane site of use in placental mitochondria. Urea denaturation experiments show that N-218 MLN64 undergoes a pH-dependent and denaturant-dependent structural transition to a molten globule state, as reported previously for N-62 StAR. N-218 MLN64 stimulated cholesterol transfer between artificial phospholipid vesicles with an initial rate of 6.5 mol/min·mol N-218 MLN64. Both N-21...
58 citations