Disease relevance of Glycylproline

• Sera from patients with hepatitis or liver cirrhosis showed an increase in the normal peak and the appearance of another new peak with glycylproline p-nitroanilide as substrate [1].
• Some dipeptide substrates tested, such as glycyl-L-arginine- and glycyl-L-proline-beta-naphthylamide, were strongly cleaved by B. gingivalis and weakly cleaved by other Bacteroides strains [2].
• Serum glycylproline dipeptidyl aminopeptidase activity in human hepatic cancer [3].
• The urine from patients with pressure sores contained significantly more gly-pro than the urine from the control [4].
• Glycylproline p-nitroanilidase activity in serum from patients with essential hypertension was significantly higher than that from normotensive healthy subjects [5].

High impact information on Glycylproline

• Transport of glycyl-L-proline by human intestinal brush border membrane vesicles [6].
• The effects of increasing concentrations of glycyl-L-proline on uptake showed that uptake of the peptide was saturable and conformed to Michaelis-Menten kinetics with a Km of 4.1 +/- 0.5 mM and a Vmax of 1.53 +/- 0.07 nmol/mg protein X 0.5 min [6].
• The results show that when the tripeptide amide came into contact with the apical enterocyte membrane, it was degraded by CD26 (dipeptidyl peptidase IV) to glycylproline and the antiretrovirally active metabolite glycinamide [7].
• Glycyl-L-proline transport in rabbit enterocyte basolateral-membrane vesicles [8].
• The optimum pH for the hydrolysis of glycyl-L-proline 4-methoxy-beta-naphthylamide was 7.5 to 8 [9].

Chemical compound and disease context of Glycylproline

• Bacteroides endodontalis produced enzymes that degraded beta-naphthylamide derivatives of glycylproline and glycylphenylalanine [10].

Biological context of Glycylproline

• The simultaneous presence of an interior negative membrane potential and an inwardly directed proton gradient did not accelerate the transport of glycyl-L-proline [11].
• Intestinal absorption of glycylproline in chicks infected with Eimeria acervulina [12].

Anatomical context of Glycylproline

• Glycylproline p-nitroanilide is hydrolysed in lymphocytes from human blood exclusively by dipeptidyl peptidase IV [13].
• Dipeptidyl peptidase IV of human lymphocytes. Evidence for specific hydrolysis of glycylproline p-nitroanilide in T-lymphocytes [13].
• The rates of transport of glycyl-L-proline into erythrocytes and kidney proximal-tubular epithelium were compared and the possible importance of erythrocyte prolidase in whole-body prolyl-peptide turnover is discussed [14].
• Hydrolysis of glycyl-L-proline by intact erythrocytes is reduced by the slow rate of iminodipeptide transport into the cell; however, intact cells hydrolyzed this substrate at a rate 10-20 times faster after preincubation with MnCl2 [15].
• Two of five clones, selected from an expression library of aortic adventitia, encode unique hypothetical proteins sharing sequences of Ig kappa, gly/pro rich (collagenous) motifs, and aromatic motifs that occur in several proteins of the extracellular matrix [16].

Associations of Glycylproline with other chemical compounds

• These data suggest that in rabbit intestinal brush-border membrane vesicles (i) glycylsarcosine and proton(s) are co-transported, (ii) this process results in a net transport of positive charge across the membrane and, (iii) a single transport system is involved in the translocation of glycyl-L-proline and glycylsarcosine [17].
• 1. Glycyl-L-proline and L-prolyl-glycine are two dipeptides that are poorly hydrolysed by brush border peptide hydrolases in vitro [18].
• On Sephadex G-200 column chromatography, normal human sera showed a single peak of enzyme activity with glycylproline p-nitroanilide as the substrate, which coincided with the peak with glycylproline beta-naphthylamide but was different from the peaks with leucine beta-naphthylamide [1].
• It was not reduced in the presence of glycyl-L-proline or of the brush-border dipeptidase inhibitors alanine-beta-naphthylamide and cilastatin [19].
• Furthermore, the intestinal permeability of captopril was significantly decreased by the withdrawal of sodium from the perfusate (3 times), and the addition of 85 mM of gly-gly (2.5 times), 15 mM of gly-pro (4 times), dipeptide mixture (4.5 times), 0.5 mM of 2,4-dinitrophenol (4 times), and 10 mM of cephradine (6 times) [20].

Gene context of Glycylproline

• At concentrations of the dipeptide that saturated prolidase, hydrolysis of glycyl-L-proline by whole cells was approximately 130 times slower than by lysates [14].
• The concentration-dependence of the rate of glycyl-L-proline hydrolysis by haemolysates was described by the Michaelis-Menten expression with Km = 14.1 +/- 2.4 mmol/litre and Vmax. = 130 +/- 10 mmol/h per litre of cell water [14].
• The concentration dependence of the rate of hydrolysis of glycyl-L-proline was discribable by the Michaelis-Menten expression with a Michaelis constant of 1.90 mmol L-1 and a maximal velocity of 9.30 mumol min-1 mg-1 protein [21].
• Among the dipeptides studied, the GB of glycylproline (GlyPro) was determined to be 214.8 kcal/mol, while prolyglycine (ProGly) was 4.2 kcal/mol more basic (GB = 219.0 kcal/mol) [22].
• Glycylproline p-nitroanilidase activity in serum of patients with advanced rheumatoid arthritis or with systemic lupus erythematosus but with normal hepatic function was found to be significantly lower than that of normal adult controls [23].

Analytical, diagnostic and therapeutic context of Glycylproline

• This relationship was tested using HPLC to measure the gly-pro in urine [4].
• In order to elucidate the mechanism of this metabolic disturbance, glycyl-L-proline was added to the cell cultures [24].
• RT-PCR expression of prolidase and hydrolytic activity against N-glycyl-l-proline (GLY-PRO), a standard substrate of prolidase, determined in tumor cell lines, exhibited a high correlation (r(2) = 0.95) [25].

References