Genetically engineered insulin - class-XII

Humulin is the brand name for synthetic human insulin produced via recombinant DNA technology, which is a protein.

Insulin consists of two polypeptide chains: the A-chain (21 amino acids) and the B-chain (30 amino acids), linked by disulfide bridges.

The insulin mRNA is translated as a single chain precursor called preproinsulin, and removal of its signal peptide during insertion into the endoplasmic reticulum generates proinsulin. Insulin and free C peptide are packaged in the Golgi into secretory granules which accumulate in the cytoplasm.

Insulin in human body is synthesized in the form of proinsulin . Proinsulin is a molecule which has 24 amino acids , B-chain peptide , C-chain peptide and A-chain peptide . The C-chain peptide of precursor insulin molecule has two amino acids . In mature insulin the C-chain peptide is cleaved off which results in the joining of A-chain peptide and B-chain peptide and form its active form. 

Humulin is the genetically engineered insulin produced by inserting human insulin gene into a host cell (E. coli) which was then allowed to grow and reproduce normally. The inserted human DNA lead them to produce a synthetic version of human insulin. Hybrid is a offspring of two genetically dissimilar animals or plants which carries genetic material from both parents and express new specific genetic characteristics. The dark bluish or brownish pigment obtained by the oxidation of haeme that has contain iron in the ferric state is known as haematin. Hybridomas are the hybrids produced by introducing specific antigen into a mouse to collect antibody-producing cells. These cells are then fused with myeloma cell to produce hybridomas which multiply indefinitely and thus provide infinite source of a specific antibody. 

• Diabetes is a disease in which your blood glucose, or blood sugar, levels are too high.
• Glucose comes from the foods you eat. Insulin is a hormone secreted by the pancreas that helps the glucose get into your cells to give them energy. With type 1 diabetes, your body does not make insulin.
  
• Hence diabetes is caused due to the deficiency of insulin in the blood is a true statement.
• So, the correct answer is 'True'.

All prokaryotic as well as eukaryotic organisms are made of double stranded DNA, that has the same type of nitrogen bases. The difference lies in the number and the arrangement of nitrogen bases 

Humulin was the first medication produced using modern genetic engineering techniques in which actual human DNA is inserted into a host cell (E. coli). The host cells are then allowed to grow and reproduce normally, and due to the inserted human DNA, they produce a synthetic version of human insulin.

Escherichia coli (E. coli) is the most commonly used host organism in genetic engineering for the production of recombinant human insulin.

Biotechnology refers to technology used to manipulate DNA. The procedures are often referred to as genetic engineering. DNA is the genetic material of all living organisms and all organisms use the same genetic code. Genes from one kind of organism can be transcribed and translated when put into another kind of organism. For example, human and other genes are routinely put into bacteria in order to synthesize products for medical treatment and commercial use. Human insulin, human growth hormone, and vaccines are produced by bacteria.

Insulin is a small globular protein consisting of 51 amino acids arranged in two chains (A and B) connected by disulfide bridges.

Genetic engineering has been successfully applied to produce human insulin by inserting the human insulin gene into bacteria.

Every somatic cell in the human body contains the complete genome, including the gene for insulin, although it is only expressed in the beta cells of the pancreas.

Proinsulin is synthesized as a single polypeptide chain that must undergo post-translational processing, specifically the removal of the C-peptide, to become mature, active insulin.

The ampicillin resistance gene acts as a selectable marker. Only cells that have taken up the recombinant plasmid (transformed cells) will survive and grow on the agar plates containing ampicillin, while untransformed cells will be killed.

In the production of human insulin using E. coli, the insulin gene is typically placed under the control of the lac promoter. Lactose (or its analog IPTG) is added to the culture medium to induce the expression of the gene.

The correct sequence starts with synthesizing the gene (i), inserting it into a plasmid (iv), introducing the plasmid into E. coli (v), culturing the bacteria (ii), extracting the product (vi), and finally purifying the protein (iii).

In early recombinant insulin production, the insulin polypeptide genes were fused to the beta-galactosidase gene (lacZ) to ensure stable expression and to produce a fusion protein.

Human insulin is produced from genetically engineered E.coli. By using genetic engineering or recombinant DNA technology, insulin-producing genes from human beings have been transferred into E.coli. bacteria, which produced insulin called 'humulin' for clinical use. This type of insulin was produced commercially by an American pharmaceutical firm Eli Lily on 5th July, 1983.

Human insulin consists of 51 amino acids, but the distribution is 21 amino acids in chain A and 30 amino acids in chain B. The option stating 30 in A and 21 in B is incorrect.

Conventional insulin derived from animals often caused allergic reactions in patients due to slight differences in protein structure. Humulin, being identical to human insulin, avoids these immunological complications.

Human insulin is produced using genetically modified E. coli, not Agrobacterium tumefaciens. Agrobacterium is primarily used for plant genetic engineering.

In 1983, Eli Lilly an American company, first prepared two DNA sequences corresponding to A and B chains of human insulin and introduced them in plasmids of Escherichia coil to produce insulin and chains. Chains A and B were produced separately, extracted and combined by creating disulphide bonds to form human insulin (humulin).

Insulin is a large popylpeptide hormone and is insoluble in lipids, therefore, it cannot enter the target cell. It acts at the cell surface. It operates through extracellular membrane bound receptor, a heterotetrameric protein (extrinsic protein) on the target cell.

In 1983, Eli Lilly an American company, first prepared two DNA sequences corresponding to A and B chains of human insulin and introduced them in plasmids of Escherichia coil to produce insulin and chains. Chains A and B were produced separately, extracted and combined by creating disulphide bonds to form human insulin (humulin).

Genetic engineering, also called as genetic modification, is the direct manipulation of an organism's genome using biotechnology. Human insulin is the name which describes synthetic insulin which is laboratory grown to mimic the insulin in humans. Human insulin is laboratory created by growing insulin proteins within E. coli bacteria (Escherichia coli). In the production of human insulin by bacteria, the human insulin gene is incorporated into the genetic material of these microorganisms. The mutant bacteria multiply forming lineages of insulin-producing bacteria. 

Human insulin is the synthetic insulin which is grown in the laboratories. Human insulin is laboratory created by growing insulin proteins within E.coli bacteria (Escherichia coli). The newly constructed plasmids containing the transplanted genetic material are introduced into a benign E. coli bacterial strain. Once inside the bacteria, the genes are activated by the bacteria to form the protein chains found in insulin

Recombinant DNA technology is widely used for the commercial production of human insulin using genetically engineered bacteria like E. coli.

In the 1980s, researchers used genetic engineering to manufacture a human insulin. In 1982, the Eli Lilly Corporation produced a human insulin that became the first approved genetically engineered pharmaceutical product. Human insulin is grown in the lab inside common bacteria. Escherichia coli is by far the most widely used type of bacterium used. Synthesizing human insulin is a multi-step biochemical process that depends on basic recombinant DNA techniques and an understanding of the insulin gene. DNA carries the small segment of the DNA, the insulin gene, which codes for the protein insulin. Manufacturers manipulate the biological precursor to insulin so that it grows inside simple bacteria.

Cyanogen bromide is a chemical reagent used in the production of humulin to cleave the fusion protein at specific methionine residues, separating the insulin polypeptide from the beta-galactosidase carrier protein.

Insulin is used for diabetes which is synthesised by a pro-hormone present in humans. The prohormone needs to be processed to become a fully mature and functional hormone as it contains an extra stretch called the C peptide which is not present in the mature insulin. 

The correct sequence is

Earlier, insulin used for curing diabetes used to be extracted from pancreas of slaughtered pigs and cattle. This insulin was slightly different from human insulin and caused some undesirable side effects such as allergy. Genetically engineered insulin is a far more efficient.

• Adenosine deaminase enzymes is crucial for the immune system to function and its absence is caused by the deletion of a gene. It is cured by the gene therapy.
  
• Insulin consists of chain A and chain B that are linked together by disulphide bridges. 
  
•  Transgenic mice are being used to test the safety of the polio vaccine.
  
• RNAi involves silencing of a specific mRNA due to a complementary dsRNA molecule that binds to and prevents translation of the mRNA. 
  

Scientists synthesized in the laboratory genes for the two insulin "A" and "B" chains. This is accomplished by chemically linking together small pieces of DNA sequence and then joining them in a specific manner to form complete genes. Once the genes were synthesized, they are attached into circular DNA strands called as plasmids. The newly constructed plasmids containing the transplanted genetic material were introduced into a benign E. coli bacterial strain.