Prior studies of the viscosity of the subunit proteoglycan obtained by dissociative extraction of bovine nasal septum cartilage suggested that the proteoglycan subunit molecule behaves as a rigid rod in aqueous solution over the range of 0.5 to 4.0 M guanidine hydrochloride. A more direct view of dimension and shape can be obtained from light-scattering and viscosity of bovine nasal cartilage p...

The thermal behavior, decomposition kinetics and mechanisms of 1-amino-1-(tetrazol-5-yldiazenyl) guanidine (tetrazene) and 2-(tetrazol-5-yldiazenyl) guanidine (MTX-1) have been investigated using DSC, TG techniques, and quantum chemical calculations. It has been found that MTX-1 is much more stable than tetrazene and MTX-1, and both of them decompose in three steps with different kinetic parame...

Replacing the guanidinium group in arginine (1) by a guanidiniocarbonyl pyrrole moiety provides a new class of artificial amino acids (2), that can be used as building blocks in standard solid phase peptide synthesis.

DNA-templated self-assembly is an emerging strategy for generating functional supramolecular systems, which requires the identification of potent multi-point binding ligands. In this line, we recently showed that bis-functionalized guanidinium compounds can interact with ssDNA and generate a supramolecular complex through the recognition of the phosphodiester backbone of DNA. In order to probe ...

Previous studies have shown canavanine to be a potent antagonist of arginine in Neurospora (1) and in some bacteria, but not in others (2, 3). Streptococcus faecaks belongs to the resistant group of bacteria and has been shown to degrade canavanine in two distinct ways: by reductive cleavage to guanidine and homoserine (4) and, to a lesser extent, by hydrolytic cleavage to ammonia and 0-ureidoh...

Momordica charantia is commonly used as a vegetable and folk medicine in most parts of South Asia. This study aims to determine and compare the antioxidant, metal chelating and antiglycation activities of aqueous extracts of M. charantia fruit flesh (MCF) and fruit pulp (MCP) fractions. Our results show that MCP has pronounced DPPH and ABTS radical scavenging potential compared to MCF. In the a...

The influence of ion dissolution in water is still controversial. The challenge posed to the existing concept of dissolved ions acting as water structure makers and structure breakers through recent studies calls for more experimental evidence. The temperature-dependent relaxation dynamics of water in bulk and in ionic salt solutions can give an idea about the hydrogen-bonded network and hence ...

In the field of organic chemistry, a base is generally defined as a reagent capable of abstracting proton to yield a carbanion species. At a basic textbook level, organobases are normally limited to amines, which are categorized as very weak bases according to the above definition. The introduction of an imine function (1⁄4NH) to the a-carbon of amines affords more basic amine species, amidines...

In an effort to produce small discrete fragments of human growth hormone (GH), we examine the action of the proteolytic enzyme, bromelain, on this molecule. Purified human GH incubated for 40 min at 220C with crude bromelain and gel-filtered on Sephadex G-100 resulted in a major digestion product, peak 2. SDS-urea gel electrophoresis in the presence of fl-mercaptoethanol suggested that peak 2 w...

Short cationic oligomers, including arginine-rich peptides and analogous beta-amino acid oligomers ("beta-peptides"), can enter the cytoplasm and nucleus of a living cell from the extracellular medium. It seems increasingly clear that multiple entry pathways are possible, depending upon the structure of the guanidinium-rich molecule, the type of cell, and other factors. We have previously shown...