The impact of glycosaminoglycan (chondroitin sulphate, CS) on bone morphogenetic protein - 2 (BMP- 2) structure, stability (thermal and chemical), association kinetics and conformation was monitored by multiple spectroscopic techniques (UV-Visible, fluorescence and circular dichroism). The absorbance in peptide region and fluorescence intensity of BMP - 2 was quenched in presence of CS; thus, confirming the formation of a ground-state complex. As there was an increase in Stern-Volmer constant observed as a function of temperature, idea of dynamic quenching was established. However, the negligible changes in lifetime indicated static quenching; thus, making the process a combination of static-dynamic quenching. Basically, the protein - glycan interaction was driven by entropy of the system and mediated by hydrophobic interactions. Secondary structure (CD spectroscopy) of native protein was significantly affected (intensity became more negative) in presence of CS, thus, introducing more compactness in the protein. CS infused thermal and chemical stability into BMP - 2 via alteration in its conformation. The rate of association was inversely proportional to concentration of quencher (CS), which confirmed the correlation between large size (similar to 5 times the size of protein) and structural complexity of CS with fewer binding sites present in BMP - 2. The rate of association in presence of urea, suggested a decrease in association rate as a function of urea concentration for 15 mu M CS. Experimental evidences suggested an interaction between protein and glycan mediated by hydrophobic interactions, which deciphers structural, thermal and chemical stability into protein. (C) 2020 Elsevier B.V. All rights reserved.

This paper describes the effects of flaxseed and its components (flax oil, secoisolariciresinoldiglucoside[SDG], flax lignan complex [FLC], and flax fibers] on serum lipids (total cholesterol [TC], low-density lipoprotein-cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], and triglycerides [TG]) in animals and humans. Ordinary flaxseed reduces TG, TC, LDL-C, and TC/HDL-C levels in a dose-dependent manner in animals. In humans, it reduces serum lipids in hypercholesterolemicpatients but has no effects in normocholesterolemicpatients. Flax oil has variable effects on serum lipids in normo- and hypercholesterolemic animals. Flax oil treatment, with a dosage containing greater than 25g/day of alpha-linolenic acid, reduces serum lipids in humans. Although FLC reduces serum lipids and raises serum HDL-C in animals, its effects on serum lipids in humans are small and variable. Flax fibers exert small effects on serum lipids in humans. Crop Development Centre (CDC)-flaxseed, which contains low concentrations of alpha-linolenic acid, has significant lipid lowering effects in animals. Pure SDG has potent hypolipidemic effects and raises HDL-C. In conclusion, flaxseed and pure SDG have significant lipid-lowering effects in animals and humans, while other components of flaxseed have small and variable effects.