Equilenin: a specific fluorescent probe for steroid-protein interactions in sex steroid-binding protein

Identification of a novel sex steroid binding protein.

We describe a cytoplasmic steroid binding protein in the chick oviduct which has intriguing characteristics. This protein binds [3H]estradiol with high affinity (Kd = 30 X 10(-9) M) and limited capacity (300 fmol/mg of cytosol protein). It sediments at 8 S in low-salt sucrose density gradients and at 4 S in high-salt gradients. Unlike the estrogen receptor, however, this protein also binds prog...

Steroid-binding receptors in fungi: implication for systemic mycoses

It has been shown that some of the mycotic infections especially systemic mycoses show increased male susceptibility and some steroids have been known to influence the immune response. Researchers found that some fungi including yeasts use "message molecules" including hormones to elicit certain responses, especially in the sexual cycle, but until recently no evidence was available to...

Organization of cytochrome P450 enzymes involved in sex steroid synthesis: PROTEIN-PROTEIN INTERACTIONS IN LIPID MEMBRANES.

Mounting evidence underscores the importance of protein-protein interactions in the functional regulation of drug-metabolizing P450s, but few studies have been conducted in membrane environments, and none have examined P450s catalyzing sex steroid synthesis. Here we report specific protein-protein interactions for full-length, human, wild type steroidogenic cytochrome P450 (P450, CYP) enzymes: ...

Identification of lysine 134 in the steroid-binding site of the sex steroid-binding protein of human plasma.

The sex steroid-binding protein of human plasma SBP (or sex hormone-binding globulin, SHBG) was specifically inhibited with the alkylating affinity label, 17 beta-[[( 2-14C]bromoacetyl)oxy]-5 alpha-androstan-3-one. The natural ligand, 5 alpha-dihydrotestosterone, was shown to protect against inactivation and labeling. The steroid-binding activity of the protein was abolished when approximately ...

Green fluorescent protein chimeras to probe protein-protein interactions.