Internalisation and multiple phosphorylation of γ-Conglutin, the lupin seed glycaemia-lowering protein, in HepG2 cells.

Lupin seed γ-Conglutin is a protein capable of reducing glycaemia in mammalians and increasing glucose uptake by model cells. This work investigated whether γ-Conglutin is internalised into the target cells and undergoes any covalent change during the process, as a first step to understanding its mechanism of action. To this purpose, γ-Conglutin-treated and untreated HepG2 cells were submitted to confocal and transmission electron microscopy.

Heterologous expression and purification of the soybean 7S globulin α' subunit extension region: in vitro evidence of its involvement in cell cholesterol homeostasis.

In a previous paper, the biological activity of a 216-amino acid recombinant truncated form of the soybean 7S globulin α' subunit, known to control cholesterol and triglyceride homeostasis, was described. In this work, a shorter version of the polypeptide chain, spanning 142 amino acid residues from the N-terminus and thus exclusively including the so-called extension region, was cloned and overexpressed in Pichia pastoris. The yield of the recombinant polypeptide, which was termed α'E, was 8-fold greater than the previous truncated version.

Lupin seed γ-conglutin lowers blood glucose in hyperglycaemic rats and increases glucose consumption of HepG2 cells.

The aim of the present study was to evaluate the effect of a chronic oral γ-conglutin treatment in male Sprague-Dawley rats in which hyperglycaemia had been induced by supplying 10 % d-glucose in drinking-water. A γ-conglutin dosage of 28 mg/kg body weight was daily administered to animals for 21 d. Plasma glucose, insulin and glucose overloading were monitored.

Cloning, yeast expression, purification and biological activity of a truncated form of the soybean 7S globulin alpha' subunit involved in Hep G2 cell cholesterol homeostasis.

A truncated form of alpha' chain (talpha'), the soybean 7S globulin subunit previously demonstrated to be active in controlling the cholesterol and triglyceride homeostasis in in vitro and in vivo models, was cloned and expressed in the yeast Pichia pastoris. The recombinant polypeptide spanned 216 amino acid residues from the N-terminal side and included the N-terminal extension region of the soybean subunit. The talpha' polypeptide was purified by conventional biochemical techniques, and its potential to modulate the activity of low-density lipoprotein (LDL) receptor was evaluated in a human hepatoma cell line (Hep G2) by monitoring the uptake and degradation of labeled LDL.

The alpha' subunit from soybean 7S globulin lowers plasma lipids and upregulates liver beta-VLDL receptors in rats fed a hypercholesterolemic diet.

Recent data concerning the effect of soybean 7S globulin subunits on the upregulation of LDL receptors in Hep G2 cells identified the alpha' subunit as the candidate responsible for this biological effect. In vivo evaluation of this subunit on cholesterol homeostasis was hampered by the lack of suitable amounts of alpha' chain. A novel separation procedure allowed us to investigate the effects of alpha' subunit administration on plasma cholesterol and triglyceride levels, as well as on the activity of liver beta-VLDL receptors of rats fed a hypercholesterolemic (HC) diet.

Proteins of white lupin seed, a naturally isoflavone-poor legume, reduce cholesterolemia in rats and increase LDL receptor activity in HepG2 cells.

White lupin (Lupinus albus, L.), a widely cultivated crop that has been consumed for many years in Western Europe, may provide a useful alternative for individuals wishing to substitute animal with plant proteins for cardiovascular disease prevention. Lupin seeds have a very low content of isoflavones, and lupin protein isolates are essentially isoflavone free.

Soy milk with a high glycitein content does not reduce low-density lipoprotein cholesterolemia in type II hypercholesterolemic patients.

In order to evaluate acceptability and effectiveness of a partial addition of soy protein to the daily diet in well-established type II hypercholesterolemic individuals, a double-blind study was carried out with a soy milk providing 25 g/day of protein versus an identically formulated cow's milk. Twenty patients with type II hypercholesterolemia, 4 males and 16 females, age range 38-76 years, all with cholesterol levels >7 mmol/l and low-density lipoprotein cholesterol <5.5 mmol/l, were selected.