Collectins are C-type animal lectins with both collagenous and carbohydrate recognition domains and are involved in the first line host defense against pathogens. We report here a novel Ca 2؉ -dependent and GlcNAcbinding lectin consisting of subunits of 35 kDa (P35) with a collagen-like sequence. When P35 is isolated from human serum, it forms a homopolymer by means of intermolecular disulfide bonding, as is the case with collectins. P35 cDNA was cloned from a human liver cDNA library, and the deduced amino acid sequence of 313 residues revealed that the mature form of P35 consists mainly of collagen-and fibrinogen-like domains. The latter contained two potential Ca 2؉-binding sites that may be involved in carbohydrate binding. The overall sequence of P35 was highly homologous to porcine ficolins ␣ and ␤. Northern blots of various human tissues showed that the major product of the 1.3-kilobase-long P35 transcript is expressed in liver. P35 enhanced phagocytosis of Salmonella typhimurium by neutrophils, suggesting an opsonic effect via the collagen region. P35 was found to bind to GlcNAc-conjugated bovine serum albumin, a neoglycoprotein, as well as to neoglycolipids containing complex-type oligosaccharides derived from glycoproteins, suggesting that P35 recognizes GlcNAc residues such as those found in microbial glycoconjugates and complex-type oligosaccharides. Therefore, P35 represents a new type of GlcNAc-binding lectin with structural and functional similarities to collectins involved in innate immunity.

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SummaryThe characteristics of removal of astringency of two Japanese persimmon (Diospyros kaki Thunb.) cultivars, `Denkuro' and `Hiratanenashi', when treated with warm water, ethanol vapor and CO2 gas, were investigated.The patterns of the changes in peel color and flesh firmness were much the same for each treatment in both cultivars.The astringency of `Denkuro' and `Hiratanenashi' fruits was removed with both warm water and CO2 treatments. Decrease of soluble tannin occurred earlier in `Denkuro' than in `Hiratanenashi' in warm water treatment. In the ethanol treatment, astringency of `Hiratanenashi' was removed gradually and thoroughly, whereas there was almost no decrease of soluble tannin in `Denkuro' for 6 days.Ethanol and acetaldehyde accumulated in the flesh earlier and their levels were a little higher in `Denkuro' than in `Hiratanenashi' fruits when treated with warm water. The patterns of ethanol and acetaldehyde accumulation were almost the same in CO2 treatment in the two cultivars. In ethanol treatment, much more ethanol accumulated in `Denkuro' than in `Hiratanenashi' fruits, but only little acetaldehyde was detected in `Denkuro' , while a small but obvious amount accumulated in `Hiratanenashi'. The decrease of soluble tannin was, on the whole, closely related to the level of acetaldehyde accumulation in both cultivars.The responses of fresh juice to acetaldehyde vapor seemed almost the same between the two cultivars.From these results, the cultivar differences between `Denkuro' and `Hiratanenashi' and their regulative mechanisms in removing astringency were discussed.