Collectins — soluble proteins containing collagenous regions and lectin domains — and their roles in innate immunity

Abstract

The collectins are a group of mammalian lectins containing collagen-like regions. They include mannan binding protein, bovine conglutinin, lung surfactant protein A, lung surfactant protein D, and a newly discovered bovine protein named collectin-43. These proteins share a very similar modular domain composition and overall 3-dimensional structure. They also appear to play similar biological roles in the preimmune defense against microorganisms in both serum and lung surfactant. The close evolutionary relationship between the collectins is further emphasized by a common pattern of exons in their genomic structures and the presence of a gene cluster on chromosome 10 in humans that contains the genes known for the human collectins. Studies on the structure/function relationships within the collectins could provide insight into the properties of a growing number of proteins also containing collagenous regions such as Clq, the hibernation protein, the a-and 0-ficolins, as well as the membrane acetylcholinesterase and the macrophage scavenger receptor.

Major House Dust Mite Allergens Dermatophagoides pteronyssinus 1 and Dermatophagoides farinae 1 Degrade and Inactivate Lung Surfactant Proteins A and D

“…Collectins are multimeric proteins, and each polypeptide chain is composed of four domains; a cysteine-rich N-terminal region, which is involved in the formation of interchain disulfide bonds, a collagen-like triple helical region, an ␣-helical coiled-coil neck region, and a C-terminal carbohydrate recognition domain (CRD) (4,5). Each polypeptide associates with two others via their N-terminal, collagen, and ␣-helical neck region, to form a trimeric subunit, and six of these trimeric subunits make up the overall "bouquet"-like structure of SP-A, whereas SP-D is composed of four trimeric subunits arranged in a cruciform-like structure (6 -8).…”

Structure of a truncated human surfactant protein D is less effective in agglutinating bacteria than the native structure and fails to inhibit haemagglutination by influenza A virus

“…This indicates that truncated conglutinin requires an 8-16-fold greater concentration for conglutination than does the native one. Conglutinin and SP-D have a characteristic cruciform structure, which is assembled as tetramers of three identical polypeptides [25]. Their agglutination activity is considered to depend on oligomerization and their ability to bridge large distances between organisms.…”

Recombinant Mannose-binding Lectin Protein and Anti-Mannose-binding Lectin Polyclonal Antibody Production

“…그러므로, MBL은 당쇄로 장식된 병원균의 초기감 염 몇 시간 내지 수일의 일차 면역 반응에 중요한 역할을 하는 것으로 제시되고 있다 [11]. 이러한 이유로 MBL은 획득면역이 작용하기 전에 제일선의 방어를 제공하며 [15] 특히, 획득면역 이 미성숙한 시기인 영아기에 있어서 중요한 역할을 하는 것 으로 알려져 있다 [9,10].…”