Nov 1, 1982

Characterization of specific low-density lipoprotein binding sites in human term placental microvillous membranes

Molecular and Cellular Endocrinology
E AlsatL Cedard


Purified microvillous membranes prepared from normal term human placenta were studied for their ability to bind specifically low-density lipoprotein (LDL). Electron microscopic examination of the membrane preparations revealed essentially microvilli-like structures, and the enzyme analyses a 14-17-fold enrichment in the membrane markers 5'-nucleotidase and alkaline phosphatase. The binding of [125I]LDL was dependent on time, temperature, pH and protein concentration; it was saturable with a low capacity (130.4 +/- 22.2 ng/mg of membrane protein) and presented a high affinity (apparent Ka 6.12 +/- 1.32 micrograms protein per ml). These high-affinity binding sites were specific for LDL (high-density lipoprotein induced less competition than unlabelled LDL) and were sensitive to pronase digestion. Unlike the binding of LDL to other tissues, the [125I]LDL binding to microvillous membranes did not require divalent cations. The presence of specific LDL receptors on the placental microvillous membranes, located at the effective site of exchange between the maternal blood and the placental tissue, supports the concept that human placenta utilizes LDL-cholesterol for its progesterone synthesis.

Mentioned in this Paper

Hormone Receptors, Cell Surface
Electron Microscopy
Low Density Lipoprotein Receptor

About this Paper

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Synthetic Genetic Array Analysis

Synthetic genetic arrays allow the systematic examination of genetic interactions. Here is the latest research focusing on synthetic genetic arrays and their analyses.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

Head And Neck Squamous Cell Carcinoma

Squamous cell carcinomas account for >90% of all tumors in the head and neck region. Head and neck squamous cell carcinoma incidence has increased dramatically recently with little improvement in patient outcomes. Here is the latest research on this aggressive malignancy.

Signaling in Adult Neurogenesis

Neural stem cells play a critical role in the production of neuronal cells in neurogenesis is of great importance. Of interest is the role signalling mechanisms in adult neurogenesis. Discover the latest research on signalling in adult neurogenesis.

Psychiatric Chronotherapy

Psychiatric Chronotherapy considers the circadian rhythm as a major factor for optimizing therapeutic efficacy of psychiatric interventions. Discover the latest research on Psychiatric Chronotherapy here.

Epigenetic Memory

Epigenetic memory refers to the heritable genetic changes that are not explained by the DNA sequence. Find the latest research on epigenetic memory here.

Bone Marrow Neoplasms

Bone Marrow Neoplasms are cancers that occur in the bone marrow. Discover the latest research on Bone Marrow Neoplasms here.