Insulin lispro acts more rapidly than regular human insulin because of which structural modification?

• A Addition of two arginine residues at the C-terminus of the B chain
• B Substitution of proline at position B28 with lysine, reducing self-association into hexamers ✓
• C Attachment of a myristic acid side chain enabling albumin binding
• D Deletion of the terminal threonine at B30 with acylation

Explanation

Lispro reverses the sequence of proline B28 and lysine B29. This disrupts the hydrophobic interactions needed for insulin dimer and hexamer formation, so the injected insulin remains largely monomeric and is absorbed within minutes rather than hours. Option A describes insulin glargine, option C describes insulin detemir, and option D describes insulin degludec. Regular insulin must dissociate from hexamers after injection, delaying its onset.

Reference: Katzung's Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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