| Size | Price | Stock | Qty |
|---|---|---|---|
| 100mg |
|
||
| 500mg |
|
||
| Other Sizes |
| Targets |
Intestinal dipeptide transport system(s) [1]
|
|---|---|
| ln Vitro |
L-leucyl-L-leucine uptake at pH 5 was studied in hamster jejunum rings.
Kinetics of uptake of free leucine over 0.1-100 mmol/L gave Kt 4.7 mmol/L and Vmax 1.8 μmol/min/g. Kinetics of L-leucyl-L-leucine uptake over 0.1-75 mmol/L: Hofstee plot was biphasic. In presence of free leucine (75 mmol/L) to inhibit uptake of liberated leucine, the plot became linear with Kt 5.2 mmol/L and Vmax 0.9 μmol/min/g. Corrected values for intact peptide uptake gave Kt 5.6 mmol/L and Vmax 0.9 μmol/min/g. Both Kt and Vmax were lower than corresponding values for L-valyl-L-valine. Proportion of L-leucyl-L-leucine taken up as free leucine vs intact peptide varied with concentration: at 0.1 mmol/L, 55% as free leucine and 45% as peptide; at 50 mmol/L, 43% as free leucine and 57% as peptide. Gly-Sar weakly inhibited L-leucyl-L-leucine uptake (<20% inhibition at 1 mmol/L substrate and 50 mmol/L inhibitor). L-leucyl-L-leucine was a powerful inhibitor of Gly-Sar uptake and could completely inhibit mediated uptake of Gly-Sar at infinitely high inhibitor concentration. Ki for inhibition of Gly-Sar uptake by L-leucyl-L-leucine was 2.4 mmol/L (calculated assuming Ki for Gly-Sar 6.1 mmol/L). Lineweaver-Burk plot of Gly-Sar uptake in presence of L-leucyl-L-leucine (2 mmol/L) was compatible with competitive inhibition. A Dixon plot confirmed competitive inhibition. A combination of Gly-Sar and free leucine (20-60 mmol/L each) caused stronger inhibition of L-leucyl-L-leucine uptake than either alone but could not cause complete inhibition (Vu 0.11 μmol/min/g at 1 mmol/L substrate). Similarly, Gly-Gly plus free leucine also caused incomplete inhibition (Vu 0.072 μmol/min/g). However, L-valyl-L-valine could completely inhibit L-leucyl-L-leucine uptake (Vu 0.034 μmol/min/g, close to d value 0.024). Conversely, L-leucyl-L-leucine could completely inhibit uptake of L-valyl-L-valine (Vu 0.009 μmol/min/g, similar to d for Val-Val). Over the whole concentration range studied, mediated uptake of leucine from L-leucyl-L-leucine was more rapid than uptake of the equivalent free leucine. [1] |
| Enzyme Assay |
Experimental procedure for uptake studies: Rings of everted hamster jejunum were incubated in 0.5 mL of medium containing radiolabeled substrate for 2 minutes at 37°C under O2 with shaking at 100 strokes/min. After incubation, rings were rinsed in cold NaCl solution (154 mmol/L), blotted, and eluted in 1 mL of sulfosalicylic acid (60 g/L) in a boiling water bath for 5 minutes. After centrifugation, 0.5 mL of supernatant was added to 15 mL of xylene-based scintillation fluid and radioactivity measured in a liquid-scintillation spectrometer. Uptake was expressed as μmol/min/g initial wet weight after correction for substrate in the inulin space. All estimates are mean values from at least six rings from at least three animals. [1]
Determination of pH effect on uptake and hydrolysis: Jejunal rings were incubated with L-leucyl-L-leucine (5 mmol/L) at various pH values. Uptake and medium free leucine concentration were measured. [1] Determination of non-mediated uptake (d value): A Preston-Schaeffer-Curran plot was used. For L-leucyl-L-leucine, d was 0.024 μmol/min/g at 1 mmol/L. For free leucine, d was 0.041 μmol/min/g at 1 mmol/L. [1] Inhibition experiments: Various concentrations of inhibitors (free leucine, Gly-Sar, Gly-Gly, L-valyl-L-valine) were added to the incubation medium containing radiolabeled substrate (1 mmol/L L-leucyl-L-leucine or other peptides). Preston-Schaeffer-Curran plots were used to estimate uptake at infinitely high inhibitor concentration. [1] Chromatographic analysis of free leucine: Free leucine in the incubation medium was analysed by ion-exchange chromatography on an automatic-loading amino acid analyser. [1] |
| References | |
| Additional Infomation |
Leucine-Leucine (Leu-Leu) is a dipeptide composed of two L-leucine residues. It is a metabolite in both the human body and Mycoplasma genitalium. Functionally, it is related to L-leucine. It is a zwitterion tautomer of leucine-leucine.
The study suggests the existence of more than one dipeptide uptake system in the small intestine, originally proposed by Rubino, Field & Shwachman, and raised by several other groups. L-leucyl-L-leucine could inhibit mediated uptake of intact glycylsarcosine completely, but glycylsarcosine could not cause complete inhibition of mediated uptake of intact L-leucyl-L-leucine. In contrast, glycylsarcosine could completely inhibit mediated uptake of intact L-valyl-L-valine, which in turn could completely inhibit uptake of intact L-leucyl-L-leucine. The inability of Gly-Sar (a structurally modified dipeptide with a methylated peptide bond) to completely inhibit L-leucyl-L-leucine uptake, even when combined with free leucine, was unexpected. Similar results with Gly-Gly make atypical structure less likely as an explanation. The observation that free leucine concentrations in bulk phase during L-leucyl-L-leucine uptake were far too low to account for calculated uptake of free leucine released from peptide extracellularly is likely an effect of the unstirred layer. The findings emphasize that intestinal uptakes of intact peptides and their constituent amino acids are independent processes with different kinetic characteristics. [1] |
| Molecular Formula |
C12H24N2O3
|
|---|---|
| Molecular Weight |
244.33056
|
| Exact Mass |
244.179
|
| CAS # |
3303-31-9
|
| PubChem CID |
76807
|
| Appearance |
White to off-white solid powder
|
| Density |
1.051g/cm3
|
| Boiling Point |
432.7ºC at 760mmHg
|
| Flash Point |
215.5ºC
|
| LogP |
2.066
|
| Hydrogen Bond Donor Count |
3
|
| Hydrogen Bond Acceptor Count |
4
|
| Rotatable Bond Count |
7
|
| Heavy Atom Count |
17
|
| Complexity |
265
|
| Defined Atom Stereocenter Count |
2
|
| SMILES |
O=C(N[C@@H](CC(C)C)C(O)=O)[C@H](CC(C)C)N
|
| HS Tariff Code |
2934.99.9001
|
| Storage |
Powder -20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment, avoid exposure to moisture. |
| Shipping Condition |
Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)
|
| Solubility (In Vitro) |
DMSO :< 1 mg/mL
|
|---|---|
| Solubility (In Vivo) |
Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.
Injection Formulations
Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)(e.g. IP/IV/IM/SC) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). View More
Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] Oral Formulations
Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). View More
Oral Formulation 3: Dissolved in PEG400 (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 4.0928 mL | 20.4641 mL | 40.9283 mL | |
| 5 mM | 0.8186 mL | 4.0928 mL | 8.1857 mL | |
| 10 mM | 0.4093 mL | 2.0464 mL | 4.0928 mL |
*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.
Calculation results
Working concentration： mg/mL；
Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O，mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.
Products are for research use only; We do not sell to patients
Copyright 2020 InvivoChem LLC | All Rights Reserved
