Transport of vitamin A to the target cells is mediated by the lipocalin retinol-binding protein. In plasma, RBP is found in a complex with its carrier protein Transthyretin (TTR). The structures of RBP free and in complex with TTR provide the details of the protein- protein interaction.

Allergy is an expanding problem in the industrialized countries. Allergenic proteins, the allergens, causing the allergic symptoms are ubiquitous materials in the environment, normally not harmful for individuals not sensitized to them. In contrast, sensitized individuals who have specific...

Evidence has been steadily accruing over time that a significant number of lipocalins interact with specific membrane receptors. The transfer of RBP:retinol across the cell membrane, faciliated by the elusive RBP receptor was for many years the archetypal example of a lipocalin:receptor mediated...

alpha(1)-Microglobulin is one of the three original members of the lipocalin superfamily. It has been found in mammals, birds, amphibians and fish and is distributed in plasma and extravascular compartments of all organs. a1-Microglobulin has a free cysteine side-chain located in a flexible loop,...

This review highlights several possible future roles of lipocalins in human clinical medicine. Generically, due to their metabolism as low molecular weight plasma proteins, lipocalins are candidate markers of kidney functions. Clinical data strongly supporting this notion are available for...

Siderocalin (Lipocalin 2), first identified as a neutrophil granule component, is also found in uterine secretions, in serum and synovium during bacterial infection and secreted from epithelial cells in response to inflammation or tumorigenesis. Siderocalin is a potent bacteriostatic agent in...

Lipocalinology, as a discipline, has been with us for more or less twenty years. After an initial period of exciting, if capricious, growth, study of the lipocalin protein family has now entered a period of solid and significant maturity. The modern era of lipocalin research is marked by the...

The lipocalin family contains more than 30 distinct proteins that are widely distributed throughout the living world. However, the exact physiological functions of many members of the family are unknown although several are inferred by analogy. Three of the core lipocalins, b-lactoglobulin, major...

Glycodelin has many names in the literature, such as placental protein 14 (PP14), human placental organ-specific a2-globulin, or progesterone-dependent endometrial protein, based on electrophoretic characteristics, regulation, or tissue of first identification.1-4 After detailed information...

Lipocalin-type prostaglandin (PG) D synthase (L-PGDS) is the first member of the lipocalin family to be recognized as an enzyme. L-PGDS catalyzes the isomerization of PGH2, a common precursor of various prostanoids, to produce PGD2, a potent endogenous somnogen and a nociceptive modulator as...

Lipocalins are remarkable in their diversity, as manifest at the levels of protein sequence and protein function. At the level of 3-dimensional structure, however, they are very similar. The lipocalins are also part of a larger protein superfamily: the calycins, which also includes the fatty...

Lipocalins are widely distributed in animals, insect and bacteria but very little is known about plant lipocalins. The first lipocalin-like proteins reported in plants were the two key enzymes of the xanthophyll cycle, the violaxanthin de-epoxidases and the zeaxanthin epoxidases. However, the...

Avariety of molecules have been identified in blood plasma that exhibit lipocalin-like properties, but they do not seem to be functionally related. This review is restricted to four of these lipocalins: a1-acid glycoprotein (AGP), apolipoprotein D (apoD), apolipoprotein M (apoM) and...

The bacterial lipocalins were discovered in 1995 and first reviewed in the year 2000. In the subsequent 5 years, two important developments have been made. First, an explosion of molecular sequence information from microbial genome projects has uncovered more than 90 bacterial lipocalin...

The number of sequenced arthropodan lipocalins adds up to over eighty (see Table1). From our currently fragmented knowledge of arthropodan genomes, the last common ancestor of this phylum is proposed to possess two lipocalins (see Chapter 3). Intra-lineage duplications enlarged the number of...

The Lipocalin protein family is discussed, in its totality, in Chapters 2 and 3 and most lipocalins are reviewed individually, or in groups, elsewhere in this volume. In this chapter, written after collecting and editing all other chapters, a few additional subjects related to the family as a...

As extensively detailed elsewhere in this book, lipocalins exhibit three characteristic features, which include: (i) an unusually low amino acid sequence similarity (typically 15-25% between paralogs) (ii) a highly conserved protein tertiary structure, and (iii) a similar arrangement of exons and...