Results 1 to 8 of 8

Thread: Info on IGF-1

  1. #1
    JohnnyB's Avatar
    JohnnyB is offline AR-Hall of Famer / Retired
    Join Date
    Apr 2002
    Location
    Califas
    Posts
    9,138

    Info on IGF-1

    Long™R3IGF-I
    Recombinant analog of human insulin growth factor-I
    CATALOG NO. 85580


    Description

    Long™R3IGF-I is a recombinant analog of human insulin-like growth factor-I (IGF-I) that has been specifically engineered for the enhancement of cell culture performance. Long™R3IGF-I is more biologically potent in vitro than either insulin or native IGF-I and has been documented to
    significantly increase recombinant protein production. It is ideal for both research and large-scale culture systems utilizing serum-free or low-level serum applications. Long™R3IGF-I is effective in any cell that contains type I IGF receptors, including most Chinese Hamster Ovary (CHO) lines, hybridomas and fibroblasts. Long™R3IGF-I is produced in a patented E. coli expression system without the use of animal-derived components.

    Precautions

    This product is for research/laboratory use. THIS PRODUCT
    IS NOT INTENDED FOR HUMAN OR THERAPEUTIC USE.

    Storage

    Long™R3IGF-I in lyophilized form should be stored at 2 to 8 C and is stable for at least 3 years. Liquid solutions of Long™R3IGF-I (prepared as described below) can be stored
    at 2 to 8 C and are stable for at least 2 years.

    Preparation Instructions

    1. Long™R3IGF-I is supplied lyophilized in an atmosphere of nitrogen at a slight vacuum (-25 kPa). Remove the metal cap from the glass vial and introduce an air filled syringe
    through the septum to equalize the pressure.

    2. Add sufficient 10 mM HCl or 100 mM acetic acid solution to the vial to achieve a peptide concentration of at least 0.1 mg/mL. Concentrations of 1 mg/mL or more are recommended.

    3. Mix the solution thoroughly to insure the peptide is completely dissolved.

    4. Filtration of a Long™R3IGF-I solution or a culture medium after the addition of Long™R3IGF-I should be performed using a low protein-binding membrane such as Polyvinyl Idene Flouride (PVDF), Poly Ethylene Sulfite (PES) or Cellulose Acetate (CA).

    Methods for Use

    Once Long™R3IGF-I has been reconstituted, it can then be added directly to cell culture medium. A titration of Long™R3IGF-I should be performed for each different application as the optimum concentration may vary depending upon the cell type used and other components present in the medium. The recommended final concentration range of Long™R3IGF-I is 10 to 50 µg/L (or ng/mL). Because Long™R3IGF-I and insulin may compete for the same cell receptors, the effectiveness of Long™R3IGF-I will be masked if it is added in conjunction with commonly employed concentrations of insulin (1 to 10 mg/L). However, inclusion of physiological levels of insulin (5 to 10 µg/L) in cell culture medium containing the recommended levels of
    Long™R3IGF-I results in beneficial synergistic effects in certain applications.

    Characteristics

    Appearance
    White powder

    Molecular weight
    9110 ± 2 daltons (Mass spectroscopy)

    Endotoxin
    < 0.1 EU/µg

    Biological Activity
    ED50 < 10 ng/mL (Bioassay assessing the stimulation of
    protein synthesis in L6 myoblasts)

    Identity/Consistency
    Confirmed by N-terminal sequence analysis and HPLC

    References
    1. Francis, G., et al. J. Mol. Endocrinol. (1992) 8:213.
    2. Thomas, J., Fung, V. Animal Cell Technology: Products of
    Today, Prospects for Tomorrow (1993) 91.
    3. Morris, A., Schmid, J. Biotechnol. Prog. (2000) 16:693.

    JohnnyB

  2. #2
    JohnnyB's Avatar
    JohnnyB is offline AR-Hall of Famer / Retired
    Join Date
    Apr 2002
    Location
    Califas
    Posts
    9,138
    This ones on hIGF-1 thanks einstein1905

    Pharmaceutical Research. Vol. 14, No.5. 1997

    Solvent Effects on the Solubility and Physical Stability of Human Insulin- Like Growth Factor I

    Purpose. The solubility and physical stability of human Insulin -like Growth Factor I (hIGF-l) were studied in aqueous solutions with differ- ent cxcipients.

    Methods. The solubility of hlGP-r was determined by UV-absorption and quantification of light blocking particles. The physical stability of hlGF-r was studied with differential scanning caJorimetry (DSC) and circular dichroism (CD) spectroscopy.

    Results. Human IGF-l precipitated at Jow temperature in the presence of J40 mM benzyl alcohol and 145 mM sodium chloride. CD data showed that the tertiary structure of hIGF-I during these condions was perturbed compared to that in 5 mM phosphate buffer. In the presence of benzyl alcohol 290 mM mannitol stabilized hIGF-I. Sodium chloride or mannitol by themselves had no effect on either the solubility or the tertiary structure. Benzyl alcohol was attracted to hIGF-l, whereas sodium chloride was preferentially excluded The attraction of benzyl alcohol WIlS reinforced by sodium chloride leading to salting-out of hlGF-l. The CD-data indicated interactions of benzyl alcohol with phenylalanine in hIGF-i. Thermal denaturation of hIGF-I occurred in all solutions with sodium chloride. whereas mannitol or benzyl alcohol had no effect on the thermal stability. The thermal stability of hIGF- I WIlS thus decreased in 145 mM sodium chloride although it WIlS excluded from hIGF-I.

    Conclusions. The self-association and thermal aggregation of hIGF-I is driven by hydrophobic interactions. Benzyl alcohol is attracted to hIGF-I and induces changes in the tertiary structure causing hydropho- bic attraction of the protein at low temperatures.

    Jonas Fransson,1,2,4 Dan Hallen,3 and Ebba Florin-Robertsson, 1

    Received October 29, 1996; accepted February 19. 1997

    1 Department of Pharmaceutical Technology, Pharmacia & upjohn, S-112 87 Stockholm, Sweden

    2 Department of Pharmaceuticlas, Faculty of Pharmacy, Uppsala University, Box 570, S-751 23 Uppsala, Sweden

    3 Department of Structural Chemistry, Parmacia & Upjohn, S-112 87 Stockholm, Sweden

    4 To whom correspondence should be addressed. (e-mail: [email protected])

    JohnnyB

  3. #3
    Da Bull's Avatar
    Da Bull is offline Banned
    Join Date
    Sep 2003
    Location
    X
    Posts
    0
    That's a different view.The site from down under seems to lean towards HCL as the solution for stability.Quite a few conflicting studies done on this topic and IGF-1 in general.

  4. #4
    JohnnyB's Avatar
    JohnnyB is offline AR-Hall of Famer / Retired
    Join Date
    Apr 2002
    Location
    Califas
    Posts
    9,138
    I know it's can be hard to sort out, but I believe that BA is fine. Of course I get my view from these studies

    JohnnyB

  5. #5
    Join Date
    Dec 2003
    Posts
    3,124
    Quote Originally Posted by JohnnyB
    I know it's can be hard to sort out, but I believe that BA is fine. Of course I get my view from these studies

    JohnnyB
    I'm with you in thinking BA is fine. Not only the study above, but I've heard of people buying already reconstituted IGF-1 in BA and storing it in the freezer for 2 months or more before use...only to get the same effects/sides that you'll expect to see with IGF-1.
    I'd still love to see any study that compares activity in a few different solvent conditions or in any solvent conditions but over time.
    It still is comforting to see GP's handling instructions saying that after reconstitution, it can be stored for up to 2 years. That should somewhat put to rest the myth of IGF-1 being so incredibly sensitive to degradation.

  6. #6
    JohnnyB's Avatar
    JohnnyB is offline AR-Hall of Famer / Retired
    Join Date
    Apr 2002
    Location
    Califas
    Posts
    9,138
    I've has mine for 4 months before suing and it's fine

    JohnnyB

  7. #7
    SLUMPBUSTR's Avatar
    SLUMPBUSTR is offline Associate Member
    Join Date
    May 2002
    Location
    Florida
    Posts
    372
    that impressive. i had mine for about 25 min before using it

  8. #8
    JohnnyB's Avatar
    JohnnyB is offline AR-Hall of Famer / Retired
    Join Date
    Apr 2002
    Location
    Califas
    Posts
    9,138
    Quote Originally Posted by SLUMPBUSTR
    that impressive. i had mine for about 25 min before using it


    JohnnyB

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •