PREPARATION AND PURIFICATION OF HIGH SPECIFIC ACTIVITY INSULIN-131IODINE
High specific activity insulin-I¹³¹ can be prepared with oxidizing agents, but these methods are associated with chemical damage of the insulin. This can be overcome by a suitable purification technique. A new method of purification of insulin-I¹³¹ was developed in which the damaged iodinated insulin is removed by buffer elution on a dextran column. In this way, using chloramine T as an oxidizing agent, and dextran column purification, it was possible to prepare insulin-I¹³¹ with a specific activity of 1 c/mg, the final product containing less than 3% damaged insulin. Crystalline bovine insulin (2.5 mu g in 0.025 ml pH 8 borate buffer) and 4.5 mc I¹³¹ in 0.05 ml sodium hydroxide were mixed with 50 mu g chloramine T in 0.025 ml borate buffer for 1 min. The reaction was terminated by adding 120 mu g sodium metabisulfite in 0.1 ml buffer. Free I¹³¹ was removed by dialyzing the iodinated-insulin mixture against distilled water. The iodinated insulin solution was passed through a 1-g Sephadex G-75 column made up with barbitone buffer pH 8.5. The damaged insulin-I/sup 131/ came out in the first 3-ml elute fraction. Purified insulin-I¹³¹ was collected in later fractions. With chloramine T oxidative system, an iodination efficiency over 50% was achieved. (H.H.D.)
- Research Organization:
- Middlesex Hospital, London
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-17-034013
- OSTI ID:
- 4669255
- Journal Information:
- Journal of Endocrinology, Journal Name: Journal of Endocrinology Journal Issue: 1 Vol. 25; ISSN 0022-0795
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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Related Subjects
AMINES
AMMONIUM COMPOUNDS
BORATES
CARBOHYDRATES
CATTLE
CHEMICALS
CHEMISTRY
CHLORIDES
CRYSTALS
DECOMPOSITION
DIALYSIS
EFFICIENCY
HORMONES
IMPURITIES
INSULIN
IODINE 131
ION EXCHANGE
ION EXCHANGE MATERIALS
LABELLED COMPOUNDS
MEMBRANES
MINERAL ACIDS
MIXING
OPERATION
OXIDATION
PREPARATION
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIOACTIVITY
RADIOBIOLOGY
RADIOCHEMISTRY
RADIOLYSIS
REFINING
SEPARATION PROCESSES
SODIUM COMPOUNDS
SODIUM HYDROXIDES
SOLUTIONS
SULFUROUS ACID
WATER