Insulin-Like Growth Factor 1 Des (1-3) Human Recombinant?

[mexmuscle]

What is tyhe difference between Insulin-Like Growth Factor 1 Human Recombinant and Insulin-Like Growth Factor 1 Des (1-3) Human Recombinant?

i AM READING about them on a website but still dont get what is the difference?

 

[papapumpsd]

What is tyhe difference between Insulin-Like Growth Factor 1 Human Recombinant and Insulin-Like Growth Factor 1 Des (1-3) Human Recombinant?

i AM READING about them on a website but still dont get what is the difference?

A quick 'N dirty answer is that the DES 1-3 analog has a much lower affinity for IGF binding proteins (IGFBP) than IGF-1. Multiple studies have indicated this.

Furthermore, "Des (1-3) IGF is a deletion of the first 3 aa that fails to bind IGF-1 binding proteins (IGFBPs), which inactivate IGF-1. Authors of Endocr Dev. 2005;9:160-9 claim “IGFBPs inactivate IGF-I by forming inactive complexes. The uses of IGF analogues with low affinity for IGFBPs and analogues that are able to displace IGF-I from IGFBPs are better candidates (than IGF-1 itself) in new clinical trials. “"
===========================
Biochem. J. (1989) 258, 267-272 (Printed in Great Britain)

Insulin-like growth factor (IGF)-binding proteins inhibit the biological activities of IGF-1 and IGF-2 but not des-(1-3)-IGF-1

Marina ROSS,* Geoffrey L. FRANCIS,* Laszlo SZABO,t John C. WALLACEt and F. John BALLARD*t
*CSIRO Division of Human Nutrition, Kintore Avenue, Adelaide SA 5000, and tBiochemistry Department,
University of Adelaide, SA 5000, Australia

"The biological potencies of IGF-1, IGF-
2 and des-(1-3)-IGF-I correlate inversely with their binding to proteins released into the medium by cells,
so that the enhanced potency of des-(1-3)-IGF-1 is a consequence of it not binding to purified binding
proteins or those released by cultured cells."

===============================

Des[1-3]-IGF-1
This protein has been isolated from bovine colostrum, human brain and porcine uterus. It is a truncated variant of human IGF-1 with an N-terminal deletion of the tripeptide Gly-Pro-Glu, which probably results from post-translational cleavage of IGF-1.

The protein binds less well to IGF-binding proteins and is generally approximately 10-fold more potent than IGF-1 at stimulating hypertrophy and proliferation of cultured cells.

REFERENCES: Ballard FJ Des(1-3)IGF-I: a truncated form of insulin-like growth factor-I. International Journal of Biochemistry and Cell Biology 28(10): 1085-1087 (1996)
-Papa!-

 

[papapumpsd]

From a manufacturer's website. This info is more on the basic description of DES 1-3, storage, and physical appearance:

Description:
IGF-I Des(1-3) Human Recombinant produced in E.Coli is a single, non-glycosylated, polypeptide chain containing 67 amino acids and having a molecular mass of 7372 Dalton.
IGF-1 Des1-3 is purified by proprietary chromatographic techniques.


Source:
Escherichia Coli.

Physical Appearance:
Sterile Filtered White lyophilized (freeze-dried) powder.

Formulation:
The protein was lyophilized after extensive dialysis against 50mM acetic acid.

Solubility:
It is recommended to reconstitute the lyophilized IGF-1 Des1-3 in sterile 18MΩ-cm H2O not less than 100 µg/ml, which can then be further diluted to other aqueous solutions.

Stability:
Lyophilized IGF-I des(1-3) although stable at room temperature for 3 weeks, should be stored desiccated below -18°C. Upon reconstitution IGF1 des-1-3 should be stored at 4°C between 2-7 days and for future use below -18°C.
For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA).
Please prevent freeze-thaw cycles.


Purity:
Greater than 95.0% as determined by:
(a) Analysis by RP-HPLC.
(b) Analysis by SDS-PAGE.


Amino acid sequence:
The sequence of the first five N-terminal amino acids was determined and was found to be Thr-Leu-Cys-Gly-Ala.

Biological Activity:
The ED50, calculated by the dose-dependant proliferation of murine BALB\C 3T3 cells (measured by 3H-thymidine uptake) is < 1.0 ng/ml, corresponding to a specific activity of 1x106 U/mg.
For most in-vitro applications, IGF-I des1-3 exerts its biological activity in the concentration range of 0.2-20 ng/ml.

Usage:
ProSpec's products are furnished for LABORATORY RESEARCH USE ONLY. The product may not be used as drugs, agricultural or pesticidal products, food additives or household chemicals.

 

[mexmuscle]

Thank you! So, Insulin-Like Growth Factor 1 Human Recombinant is better for mass building purposes than the second one?

 

[papapumpsd]

Thank you! So, Insulin-Like Growth Factor 1 Human Recombinant is better for mass building purposes than the second one?

Well Mex, you have to be careful when talking about "IGF-1". lr3IGF-1? Endogenous IGF-1???

Also, you ask about "mass building".....muscle mass? Overall bodymass? See, IGF-1 affects not only muscle tissue, but other tissues as well (intestional, organs, etc). Also, muscle mass may mean increased weight per gram of muscle (for example) which may imply water weight or glycogen (or both), OR, increased muscle mass may be from an increased number of new muscle cells. This stuff isn't real straight-forward.

What the above study implies is that DES 1-3 has "approximately 10-fold more potent than IGF-1 at stimulating hypertrophy and proliferation of cultured cells" vs. endogenous IGF-1, due to DES 1-3's lack of affinity for IGFBPs.

Now, pick apart that claim....it's talking about hypertrophy and proliferation of CULTURED CELLS. This is NOT a human study. Cultured cells are vastly different than a human being. And what does "potent" mean? There were no claims on DES 1-3's ability to generate 10x muscle mass gains in humans or even pigs (or rats).

Furthermore, Lr3IGF-1 was designed artificially to resist binding (deactivation) as is DES 1-3. I think a great study would be to compre the "effectiveness" of these to analogs at increasing muslce "hypertrophy" and/or "hyperplasia".

I am extremely unfamiliar with DES 1-3 and haven't even read one full study on it. So, I recommend that you read and read and read on this analog and see what researchers have discovered it to do in animal models. This is interesting conversation though!

 

[papapumpsd]

Journal of Endocrinology, Vol 140, Issue 1, 23-32
Copyright © 1994 by Society for Endocrinology



Effects of insulin-like growth factor-I peptides in rats with acute renal failure

AA Martin, CM Gillespie, L Moore, FJ Ballard, and LC Read



The effect of insulin-like growth factor-I (IGF-I) administration on body weight gain and the rate of recovery of renal function was investigated in rats following an acute episode of renal ischaemia. Since the des(1-3)IGF-I and LR3IGF-I variant forms of IGF-I have been shown to be more potent than IGF-I, their effects were also examined. Acute renal failure was produced in male Sprague-Dawley rats by clamping both renal arteries for 45 min. Treatment was commenced at the time of renal artery occlusion with vehicle (0.1 mol acetic acid/l; control group), IGF-I (2.0 mg/kg per day), des(1-3)IGF-I (2.0 mg/kg per day) or LR3IGF-I (1.5 mg/kg per day) by s.c. osmotic pump, and continued for 7 days, with rats being held in metabolism cages. Glomerular filtration rate (GFR) was estimated by the use of 51Cr-EDTA continuously infused i.p. via osmotic pump. Following the episode of renal ischaemia, body weight gain and nitrogen retention were significantly improved in all three peptide-treated groups, and serum urea concentrations were reduced in the groups treated with IGF-I and des(1-3)IGF-I. However, there was no evidence of the variants having any increased potency over the growth effects of IGF-I itself. GFR was significantly reduced, urine output was increased and urinary concentrating ability was reduced in all groups compared with normal rats, with no significant effect of the IGF peptides being apparent. A closer examination of the acute effects of LR3IGF-I on renal function was undertaken by measuring GFR for 3 days before and 3 days after renal ischaemia in two groups of rats, treated for the latter 3 days with either vehicle (controls) or LR3IGF-I (1.5 mg/kg per day). LR3IGF-I treatment following renal ischaemia resulted in a significantly greater fall in GFR than in controls, urinary osmolality was also significantly reduced, and fractional excretion of sodium was increased. In addition, there was histological evidence of a greater degree of tubular epithelial calcification in the kidneys of the rats treated with LR3IGF-I. This study showed that administration of IGF peptides at doses sufficient to cause significant improvement in anabolic status did not improve renal function in rats following an acute episode of renal ischaemia. Indeed the LR3IGF-I variant of IGF-I had a deleterious effect on renal function in the early stage of the recovery period.

 

[mexmuscle]

Thanks, Papa. I will pm you instead and send you the link which originated my doubts.

Well Mex, you have to be careful when talking about "IGF-1". lr3IGF-1? Endogenous IGF-1???

Also, you ask about "mass building".....muscle mass? Overall bodymass? See, IGF-1 affects not only muscle tissue, but other tissues as well (intestional, organs, etc). Also, muscle mass may mean increased weight per gram of muscle (for example) which may imply water weight or glycogen (or both), OR, increased muscle mass may be from an increased number of new muscle cells. This stuff isn't real straight-forward.

What the above study implies is that DES 1-3 has "approximately 10-fold more potent than IGF-1 at stimulating hypertrophy and proliferation of cultured cells" vs. endogenous IGF-1, due to DES 1-3's lack of affinity for IGFBPs.

Now, pick apart that claim....it's talking about hypertrophy and proliferation of CULTURED CELLS. This is NOT a human study. Cultured cells are vastly different than a human being. And what does "potent" mean? There were no claims on DES 1-3's ability to generate 10x muscle mass gains in humans or even pigs (or rats).

Furthermore, Lr3IGF-1 was designed artificially to resist binding (deactivation) as is DES 1-3. I think a great study would be to compre the "effectiveness" of these to analogs at increasing muslce "hypertrophy" and/or "hyperplasia".

I am extremely unfamiliar with DES 1-3 and haven't even read one full study on it. So, I recommend that you read and read and read on this analog and see what researchers have discovered it to do in animal models. This is interesting conversation though!

 

[Grunt76]

Very interesting study. I really want to see someone try DES[1-3]IGF-1 (human) VS LR3.

Anyone?