The properties of carnosine (Car) and glycylglycine (Gly-Gly), transported across the mucosal border, were studied in isolated guinea pig everted ileum. The initial influxes of both dipeptides could be described by single Michaelis-Menten kinetics, having a nearly equal value of maximum influx. Mutual inhibition studies showed that the inhibition observed between Car and Gly-Gly was fully compe...

An ab initio calculation of double zeta quality on glycyl-glycine at the crystal structure yielded nuclear quadrupole coupling constants at the peptide centres very close to experiment; yzz — 3.03, XyV + 2.14, /.v.v + 0.89 MHz. The first two couplings lie in the local jr-direction, and along the C-N bond, respectively. At the NHf centre the values were less satisfactory, but the (low) positive ...

Six systems of the type amino acidor peptide-guanidinium chloride-water have been investigated over wide solute molality ranges using vapor pressure osmometry. The amino acids used were glycine and L-leucine, while the peptides were diglycine, triglycine, glycyl-L-leucine and L-leucyl-L-leucine. Equations for the ratios of the activity coefficients of these compounds in the salt solutions and w...

A new colorimetric micromethod for the estimation of y-glutamyl transpeptidase activity has been developed, in order to obtain more reliable results with greater ease on smaller samples of a wider variety. Enzyme activity can be determined on 0.1 m/ of serum or less, or the equivalent of spinal fluid or tissue extracts, because the precipitation of proteins has been omitted. Therefore, correcti...

An outstanding problem in protein chemistry is the determination of the arrangement or sequence of amino acid residues in the peptide chains. One approach to the partial solution of this problem is through a study of the smaller degradation products present in partial hydrolysates of proteins, preferably those produced on treatment with acid (1). This method is especially attractive when the pr...

The discovery of ubiquitin-like small archaeal modifier protein 2 (SAMP2) that forms covalent polymeric chains in Haloferax volcanii has generated tremendous interest in the function and regulation of this protein. At present, it remains unclear whether the Hfx. volcanii modifier protein SAMP1 has such polyubiquitinating-like activity. Although SAMP1 and SAMP2 use the same conjugation machinery...

1. Samples of portal venous and femoral arterial plasma and mesenteric lymph were collected from unanaesthetized rats before and during the intra-duodenal infusion of high concentrations (100 mmoljl) of glycine or glycine oligopeptides (up to and including tetraglycine). 2. There was a marked increase in the concentration of free glycine, and a small amount of diglycine was detected in all the ...

To investigate a putatively primordial protein we have simplified the sequence of a 56-residue alpha/beta fold (the immunoglobulin-binding domain of protein G) by replacing it with polyalanine, polythreonine, and diglycine segments at regions of the sequence that in the folded structure are alpha-helical, beta-strand, and turns, respectively. Remarkably, multiple folding and unfolding events ar...

A rationally designed glycyl-glycine derivative containing a light cleaved pyrenylmethyl ester tail was covalently bound onto the surface of quartz template. The interface self-assembly of this dipeptide building block induced the formation of chemically bound vertically aligned nanorods (CBVANs) with light sensitivity on the template.