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A protease inhibitor, named tugalistatin, was isolated from the muscle of the marine gastropod Tugali gigas. Tugalistatin inhibited the proteolytic activity of trypsin and α-chymotrypsin. It also suppressed the activity of kallikrein as well as elastase to some extent. On the other hand, it was inactive against metallo-proteases and cysteine proteases. These suggest that tugalistatin is a serine protease inhibitor. In SDS-polyacryamide gel electrophoresis it showed a single band corresponding to 22, 000 under reduced conditions. The molecular weight of intact inhibitor was calculated to be 17, 000 when checked by FPLC on a Superose 12 column. Amino acid analysis revealed tugalistatin contained a large amount of glutamic acid (14.0%), half-cystine (11.1%), and aspartic acid (9.7%) in the molecule.

The multiple lectins in the acorn barnacle Megabalanus rosa collected from Sukumo Bay, Kochi, and Okirai Bay, Iwate, were analyzed for seasonal dynamics, agglutinating activities against animal erythrocytes, and peptide maps. Although there was no recognizable morphological difference between specimens collected from the two localities, heterogeneity in amino acid sequence was observed for the multiple lectins isolated from the barnacles. The present study shows that there is intraspecies genetic variations within M. rosa populations distributed along the Japanese coast.

A method was developed for analysis of sugar compositions of glycoproteins electroblotted onto polyvinylidene difluoride (PVDF) membranes after SDS-polyacrylamide gel electrophoresis. It was based on hydrolysis of glycoproteins on PVDF membranes and precolumn derivatization of liberated neutral sugars, sialic acids and aminosugars, respectively, and isocratic reversed-phase high-performance liquid chromatographies of these derivatives. The presence of sialo-glycoproteins in echinoderm shell matrixes was demonstrated by this method.

A method was developed for the analysis of reducing sugars extracted with 80% aqueous ethanol from fish muscle. It was based on the reaction of the reducing sugars with the chromo-phoric reagent, 4-N, N-dimethylamino-4'-azobenzene sulfonyl hydrazide, and their separation by reversed-phase high-performance liquid chromatography (HPLC) or high-performance silical gel thin-layer chromatography. The absorbance at 485nm provided a sensitivity of the picomole level. This method was applied to the reducing sugar analysis of 20mg of fish muscle. The change of reducing sugar contents in fish muscle of various stages of freshness was compared with that of K values measured by ion-pair reversed-phase HPLC.

A saline extract of chum salmon Oncorhynchus keta ova agglutinated rabbit erythrocytes but not human type B cells or sheep erythrocytes, and the hemagglutinating activity was independent of divalent cations. L-Rhamnose was the most effective inhibitor of a chum salmon ova lectin. Melibiose, L-arabinose, and D-galactose also inhibited the agglutination to some extent. The lectin was purified by affinity chromatography on L-rhamnose-Sepharose 6B and fast protein liquid chromatography on a Superose 12 column. The purified elctin showed a single band with a molecular weight of 22, 000 in SDS-polyacrylamide gel electrophoresis with and without 2-mer-captoethanol. The agglutinin activity varied with the stages of development. The activity reduc-ed markedly after the eyed stage and disappeared just before hatching. The purified lectin did ag-glutinate a fish pathogenic bacterium Vibrio anguillarum, but did not show the growth inhibition of bacterium.

Aplysia juliana had antibacterial and antitumor glycoproteins in its reproductive organs. A major active factor isolated from the genital mass was a glycoprotein having a molecular weight of 375, 000. It was composed of non-covalently bonded subunits of a molecular weight of 78, 000. A similar glycoprotein was also isolated from the eggs laid. These molecules are closely related in their antigenic specificity to the antibacterial glycoproteins (aplysianins) found in the corresponding organs of A. kurodai. Antibacterial activity of fertilized eggs disappeared by the time embryos assumed their veliger forms. From these observations we assume that aplysianins and related glycoproteins serve as a part of defense system of eggs in early stages of prehatching development of Aplysiidae.

The coelomic fluid of Balanus balanoides was found to agglutinate mouse keukemia cell L5178Y and a marine bacterium Vibrio sp. in addition to various kind of animal erythrocytes. It stimulated the phagocytosis of rabbit erythrocytes by mouse macrophage. The agglutinin was purified and found to be a glycoprotein having a molecular weight of 330, 000 daltons. It contained three different subunits. The main subunits had a molecular weight of 70, 000 daltons. Isoelectro-focusing gave two bands; the main band at pI 4.7 and the minor one at pI 5.3. The hemag-glutinating activity of the purified agglutinin was inhibited by D-galacturonic acid, D-glucuronic acid and N-acetylneuraminic acid. The glycoprotein contained high amount of aspartic acid and glutamic acid, and little histidine. There was no preasence of half cystine and arginine.

Dansyl and dabsyl amino acids were separated by reverse-phase high-performance liquid chromatography on a short column (4.6×50mm) packed with 3μm ODS particles using a gradient formed from acetone and 10 mM sodium phosphate buffer, pH 6.5 or 7. 0. The light absorption of the derivatives was used for the detection giving a sensitivity of less than 50 pmol for a dansyl derivative or 10 pmol for a dabsyl derivative. This system was applicable to the amino acid analyses, amino-terminal analyses, and carboxyl-terminal analyses with less than 1 nmol of peptides.