Figure 1.

Gallery of human and animal lipocalins. PDB codes for experimental structures are given in parentheses. hLCN2: human LCN2 in complex with the siderophore enterobactin shown as sticks chelating the central Fe³⁺ ion shown as a gray sphere (1L6M 82). hLCN1: human tear lipocalin in complex with 1,4‐butanediol (3EYC 83). Bos d 5: bovine β‐lactoglobulin unliganded form (3NPO 84). Equ c 1: major horse allergen (1EW3 85). Can f 2: dog allergen (3L4R 45) with IgE cross‐reactivity with the cat allergen Fel d 4. Can f 4: dog dander allergen (4ODD 86). Fel d 4: cat allergen, homology model structure based on template Equ c 1. Mus m 1: pheromone binding rodent major urinary protein in complex with 2‐(sec‐butyl)‐thiazole and Cd²⁺ ions shown as yellow spheres (1MUP 87).