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Investigates the amino acid sequence and antimicrobial activity of chitin-binding peptides, Pp-AMP 1 and Pp-AMP 2, from Japanese bamboo shoots (Phyllostachys pubescens). Structural features of the chitin-binding peptides; High degree of homology shown by the peptides to mistletoe toxins.

Describes the purification and properties of two novel chitin-binding antimicrobial peptides from Tulipa gesneriana L. using chitin affinity chromatography. Characteristic properties of antimicrobial peptides; Antimicrobial activity of these two antimicrobial peptides against various pathogenic microorganisms; Function of antimicrobial peptides as self-defense against infection by various harmful pathogens.

Describes the purification and some properties of novel antimicrobial peptides (AMP) from Fagopyrum esculentum, which have a potent and wide antimicrobial activity against various pathogens. Methods used for purification; Concentration of peptides required for 50 percent inhibition of the growth of plant pathogenic fungi and Gram-positive and -negative bacteria.

Pokeweed antiviral proteins (PAPs) are single-chain ribosome-inactivating proteins (RIPs) isolated from several organs of Phytolacca americana (Pokeweed) that are characterized by their ability to depurinate not only ribosomes but also various nucleic acids. PAP-S is one of the isoforms found in seeds. In this study, we obtained three different genomic clones encoding two forms of PAP-S (here designated as PAP-S1 and PAP-S2) and α-PAP after PCR using a pair of degenerated primers based on the known N- and C-terminal amino acid sequences of PAP-S. The nucleotide sequences of the genomic clones contained no introns. The deduced amino acid sequences of PAP-S1 and PAP-S2, which showed 83% identity to each other, were found to correspond to sequences reported independently for PAP-S protein and cDNA, respectively, demonstrating that at least two forms of PAP-S actually exist in seeds of the same plant. The recombinant PAP-S1, PAP-S2, α-PAP, and PAP I (a form appearing in spring leaves) exhibit the same level of depurinating activity on rat ribosomes, while their efficiencies on Escherichia coli ribosomes and salmon sperm DNA differ substantially from one another in the order of PAP I>α-PAP > PAP-S1 > PAP-S2 and α-PAP > PAP I > PAP-S1 > PAP-S2. Structural comparisons suggest that the large difference in ribosome recognition between PAP-S1 (or S2) and PAP I is caused by the alteration of residues adjacent to the adenine-binding site. [ABSTRACT FROM AUTHOR]

To define the mechanism of transport of Immunoglobulins into saliva, secretory component (SC), IgA, IgM, and J chains were localized immunocyto-chemically in human submandibular and parotid glands by the peroxidase-labeled antibody method. Ultrastructurally, SC was found to be associated with the external surfaces of the basolateral plasma membranes, perinuclear spaces, clsternae of the rough endoplasmic reticulum, saccules in the Golgl complexes, and vesicles in the cytoplasm of serous-type aclnar cells as well as ductal epithelial cells. IgA and IgM were also localized on the external surfaces of the plasma membranes and vesicles in the cytoplasm, but not on secretory granules of these epithelial cells. J chains were present in numerous plasma cells in the interstitium, and they mostly corresponded to the cells with IgA or IgM. The J chains were hardly able to be visualized in the epithelial cells by immunostaining before acid-urea treatment, which unmasked the immunoreactive sites of the J chains on the basolateral plasma membranes and hi the cytoplasmic vesicles of these cells. SC, IgA, IgM, and J chains were not evident in the mucous-type acinar cells. The findings indicate that: 1) SC is synthesized in serous-type acinar cells and ductal epithelial cells of salivary glands; 2) The J chain-containing polymeric IgA and IgM are complexed with SC on the basolateral plasma membranes of these cells; 3) The complexes are translocated through the cells in the form of endocytic vesicles toward the glandular lumlna. [ABSTRACT FROM PUBLISHER]

The phosphatase of a psychrophile was purified by ammonium sulfate fractionation, and a sequence of chromatographies on DEAE-Cellulofine, butyl-Cellulofine, Sephacryl S-100, and Mono-Q columns. The purified enzyme preparation was found to be electrophoretically homogeneous on native- and SDS-PAGE, and its molecular mass was determined to be 38.4 kDa by MALDI-TOF mass spectrometry. Maximal activity was observed at 30°C and pH 6.0. Furthermore, the activity of this enzyme at 0 and 5°C was 27 and 28%, respectively, of that at 30°C. The enzyme was stable in the pH range of 6.0 to 8.0 and up to 20°C. The enzyme was affected by metal ions; the activity was enhanced by Mg2+ and Ca2+ ions, but depressed by Zn2+ ions. Analysis of the amino acid composition indicated that this phosphatase contains no S-S bond, and only a few prolyl residues necessary to retain the rigid structure of a protein molecule. The phosphatase shows typical features of a cold enzyme; high catalytic activity at low temperature and rapid inactivation at an intermediate temperature. [ABSTRACT FROM AUTHOR]