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Volume 113 (1993)
- Issue 6 Pages 643-
- Issue 5 Pages 519-
- Issue 4 Pages 411-
- Issue 3 Pages 271-
- Issue 2 Pages 123-
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Volume 113, Issue 4
Displaying 1-17 of 17 articles from this issue
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Koji Tomoo, Shinobu Fujii, Toshimasa Ishida, Masatoshi Inoue, Kiyoshi ...1993 Volume 113 Issue 4 Pages 411-412
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSPhospholipase A2 from the venom of Agkistrodon halys blomhoffii has been crystallized as a complex with a specific inhibitor, (S)-2-dodecanoyl-amino-3-hexanol-1-phosphoglycol. The complex crystals belong to the hexagonal space group, P6122 (or P6522), with cell dimensions of a=b=61.13 Å, and c=173.15 Å. The diffraction extends to at least 2.3 Å resolution.View full abstractDownload PDF (1760K) -
Naoki Ohkura, Seiji Inoue, Kiyoshi Ikeda, Kyozo Hayashi1993 Volume 113 Issue 4 Pages 413-419
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSPhospholipase A2 inhibitor (PLI) was purified from the blood plasma of Chinese Mamushi, Agkistrodon blomhoflii siniticus, by sequential chromatography on Sephadex G-200, Mono Q, and Blue-Sepharose CL-6 B columns. The purified PLI was a glycoprotein with an apparent molecular mass of 75 kDa and was composed of a single subunit with a mass of about 20 kDa. From the results of a cross-linking experiment, the PLI was found to present as a homotrimer of the subunit. The fundamental properties of A. blomhoffii siniticus PLI were very similar to those of Habu Trimeresurus flavoviridis PLI [Kogaki et al. (1989) J. Biochem. 106, 966-971], although the latter was composed of two homologous subunits, PLI-A and PLI-B [Inoue et al. (1991) J. Biol. Chem. 266, 1001-1007]. The amino acid sequence of the subunit of A. blomhoffii siniticus PLI was determined by alignment of the peptides obtained by lysyl endopeptidase digestion or Staphylococcus aureus V 8 protease digestion. The subunit was composed of 147 amino acid residues with one residue, Asn103 being N-glycosylated. The molecular weight of its protein portion was calculated to be 16, 444 Da. The amino acid sequence of A. blomhoffii siniticus PLI subunit showed about 75% homology to those of T. flavoviridis PLI subunits, and also showed significant homologies to those of the carbohydrate recognition domains of C-type lectins.View full abstractDownload PDF (1808K) -
Kyoung-Sook Kim, Kazutaka Kano, Norio Hirabayashi, Sarah Shefer, Geral ...1993 Volume 113 Issue 4 Pages 420-424
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSWe examined the effect of cholestanol (5α-dihydrocholesterol) on cholesterol and bile acid metabolism in BALB/c mice. After feeding 1% cholestanol in the diet for 14 months, gallstones composed of 55% cholesterol and 45% cholestanol developed in 20% of the mice and were associated with mucosal inflammation and serosal vessel thickening of the gallbladder. Cholestanol concentrations increased 42-fold in the serum (0.17 versus 0.004mg/ml) and 18-fold in the liver (0.55 versus 0.03mg/g) as compared with control mice, whereas cholesterol declined 20 and 26% in serum and liver, respectively. Hepatic microsomal HMG-CoA reductase activity, reflecting cholesterol synthesis, rose 51% (from 7.2 to 10.9 pmol/mg/min). In contrast, hepatic microsomal cholesterol 7α-hydroxylase activity, the rate-determining enzyme for bile acid synthesis, was severely depressed as compared with control mice (0.9 versus 2.2 pmol/mg/min). Discontinuing cholestanol from the diet for 1 month reduced the elevated serum and liver cholestanol concentrations and restored hepatic HMG-CoA reductase and cholesterol 7α-hydroxylase activities to normal. These results demonstrate that cholestanol is absorbed, replaces cholesterol in serum and liver, causes increased cholesterol synthesis, but inhibits bile acid synthesis. The combination of increased cholesterol synthesis with decreased bile acid formation promotes gallstone formation in cholestanol-fed mice.View full abstractDownload PDF (1285K) -
Norio Inobuchi, Takashi Koyama, Fumio Sawada, Masachika Irie1993 Volume 113 Issue 4 Pages 425-432
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSTwo ribonucleases (RNase Phya and RNase Phyb) were purified to homogeneity on SDS-PAGE from the culture filtrate of the fungus Physarum polycephalum. The apparent molecular weights of RNases Phya and Phyb were about 20, 000. The pH optima of these two RNases were around 4.5-4.75. The RNases released mononucleotides from RNA in the order of 3'-GMP, 3'-AMP, and 3'-pyrimidine nucleotides. RNase Phya and RNase Phyb have the N-terminal amino acid sequences STSFD--- and KSTSF--, respectively. This finding and the similar amino acid compositions of both RNases indicated that they might share the same protein moiety except for the N-terminus Lys. The complete primary structure of RNase Phyb was determined, mostly by analysis of the peptides generated by trypsin, V 8 protease, and lysylendopeptidase digestions. The molecular weight of the protein moiety was 19, 704. The locations of four half cystine residues were almost superimposable on those in five known fungal RNase T2 family RNases, but two others were not. The sequence homology between RNase Phyb and five known fungal RNases amounted to 53-59 residues, which are concentrated around the three histidine residues, supposed to form the active site in enzymes of the RNase T2 family. However, the amino acid sequence of RNase Phyb more closely resembles those of plant RNases such as RNases from Nicotiana alata [McClure, B. A. et al. (1989) Nature 342, 955-957], tomato [RNase Le, Yost et al. (1991) Eur. J. Biochem. 198, 1-6], and Momoridica charantia [RNase MC1, Ide et al. (1991) FEBS Lett. 284, 161-164].View full abstractDownload PDF (1809K) -
Susumu Yamamoto, Toshimi Mizoguchi, Taro Tamaki, Masao Ohkuchi, Shiger ...1993 Volume 113 Issue 4 Pages 433-440
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSTwo major molecular forms of thrombomodulin fragments present in urine were isolated from human urine by four sequential steps of column chromatography. The apparent molecular weights of these thrombomodulins estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis were 98, 000 (type I) and 90, 000 (type II) with dithiothreitol, and 60, 000 (type I) and 55, 000 (type II) without dithiothreitol. The isoelectric points of the type I and type II molecules were 2.5 and 3.8, respectively. From sequence analyses, both forms were revealed to have identical 468 amino acid sequences, Ala1-Asp468, lacking 29 amino acids of the carboxyl-terminal sequence of intact cellular thrombomodulin. Major structural differences between type I and type II were observed in the carbohydrate composition: type II had less galactosamine content than type I. Both types were active in thrombin inhibition and protein C activation, although the activities were significantly less than those of intact cellular thrombomodulin. Type I had twice as much inhibitory activity on thrombin clotting activity as type II, whereas type II was more effective as a cofactor for thrombin-catalyzed protein C activation than type I.View full abstractDownload PDF (3798K) -
Minoru Kuribayashi, Hidenori Yamada, Toshihiro Ohmori, Minoru Yanai, T ...1993 Volume 113 Issue 4 Pages 441-449
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSBy employing various synthetic substrates, as well as soluble denatured protein substrate (TAP-lysozyme) and its derivatives, endopeptidase activity of cathepsin C, dipeptidyl aminopeptidase I [EC 3. 4. 14. 1], from bovine spleen was investigated. Cathepsin C efficiently degraded Z-Phe-Arg-MCA, Pro-Phe-Arg-MCA, and Suc-Leu-Leu-Val-Tyr-MCA. This endopeptidase activity required sulfhydryl reagents and halide ions, as in the case of the dipeptidyl aminopeptidase (DAP) activity. We confirmed that this endopeptidase activity is due to cathepsin C itself based on the results on gel-filtration and anion-exchange chromatographies, comparative studies of the inhibitory effects of leupeptin and E-64 on this activity and those of cathepsins B and L, and further the competitive inhibitions by mutual substrates for the DAP and endopeptidase activities of cathepsin C. We also found that cathepsin C endopeptidase activity towards TAP-lysozyme and its N-α-acetylated tryptic peptides showed marked dependence on sulfhydryl reagents and chloride ion. Thus, we concluded that cathepsin C has endopeptidase activity as well as DAP activity. The binding energy between the enzyme and the amino acid side chains of the substrate may be as important for the endopeptidase activity as is the electrostatic interaction between the enzyme and the free α-amino group of the substrate for the DAP activity.View full abstractDownload PDF (1050K) -
R. Edgardo Catalán, Ana M. Martínez, María D. Ara ...1993 Volume 113 Issue 4 Pages 450-455
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSIn the present study we described the effects of a new 1, 4-dihydropyridine derivative with antithrombotic activity on phosphoinositide turnover in washed platelets stimulated by either platelet-activating factor or thrombin. In 32P-labeled rabbit platelets, both PAF and thrombin evoked a transient loss of [32P] phosphatidylinositol 4, 5-bisphosphate (PIP2) and, thereafter, labeling increased over the control value. Concomitantly, a progressive formation of phosphatidic acid was observed. In [3H]arachidonate labeled platelets, both agonists elicited an increase in diacylglycerol (DAG) levels and arachidonate release. Pretreatment of platelets with the new dihydropyridine derivative (PCA-4230) prevents, in a dose-dependent fashion, the PAF-evoked variations in phosphoinositide turnover and DAG production. However, thrombin-induced variations were rather enhanced by PCA-4230. With respect to arachidonate release and platelet aggregation, the drug was again selective against PAF and thrombin. Although PCA-4230 shows some PAF antagonistic activity, its effects on PAF-evoked responses did not seem only due to an antagonism at receptor level. In view of the present results, the drug is not only able to discern the pathways of platelet activation by which PAF and thrombin exert their action, but it also affects selectively the enhanced phosphoinositide turnover and arachidonate release evoked by thrombin. Thereafter, PCA-4230 is a suitable tool to explore the mechanisms of action of the natural agonists.View full abstractDownload PDF (1539K) -
Akio Saito, Hyogo Sinohara1993 Volume 113 Issue 4 Pages 456-461
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA cDNA clone coding for the isoform S-1 of α-1-antiproteinase (also called α-1-proteinase inhibitor or α-1-antitrypsin) was isolated from rabbit liver cDNA library and sequenced. The cDNA consists of 1, 426 nucleotides including 5' and 3' noncoding regions and codes for 413 amino acid residues including a signal peptide of 24 residues. The nucleotide and deduced amino acid sequences show 95.5 and 95.2% homologies, respectively, with the F isoform which occurs more abundantly in the rabbit serum than the S isoform. Of the 20 amino acid differences between the two isoforms, nine are located in a stretch of 15 amino acids encompassing the reactive site region, suggesting that these genes have diverged from each other by a nonrandom mechanism. A hypothesis is proposed that the domestication of animal is responsible for the extremely high evolutionary rate in the serpin reactive site region. Prokaryotic expression plasmids were constructed from the cDNA, transfected into Escherichia coli, and expressed. Partially purified recombinant protein inhibited elastase, but did not inhibit trypsin when a small substrate was used. The recombinant S-1 form, however, protected trypsin from inactivation by soybean trypsin inhibitor, a property characteristic of α-macroglobulins or rodent murinoglobulins. It is known that there are two types of interaction between serpin and proteinase: (i) most serpins form a stable equimolar complex with the enzyme, resulting in the enzyme inhibition and (ii) some serpins act as a substrate rather than as an inhibitor, resulting in the loss of inhibitory activity. The present results show a third type of interaction, in which serpin hinders the access of a large substrate or inhibitor to the proteinase active site but does not inhibit the proteinase activity itself. Rabbit α-1-antiproteinase S-1 interacts with elastase as a type 1 inhibitor, but with trypsin as a type 3 inhibitor.View full abstractDownload PDF (732K) -
Sakae Shimizu, Shoji Ohkuma1993 Volume 113 Issue 4 Pages 462-466
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSClofibrate increased inorganic pyrophosphatase (PPase) activity in peroxisomes more than 12-fold (740 milliunits/head, 15.9±5.0 milliunits/mg protein) in rat liver. The distribution of cytochrome c oxidase and that of the PPase in a Nycodenz gradient suggested that the PPase is an original peroxisomal enzyme and not a mitochondrial contaminant: This was confirmed by second Nycodenz gradient centrifugation. The optimum pH of the peroxisomal PPase was about 8.5. The activity was specific to inorganic pyrophosphate (PP1), the Km value for PP1 being 34.1±3.3 3.3μM. It was strictly dependent on Mg2+ and showed a sigmoidal dose-response for Mg2+ with an S0.5 value of 100μM. The activity was inhibited by Ca2+, p-chloromercuriphenylsulfonic acid, Hg2+, N-ethylmaleimide, and NaF. The functions of peroxisomal PPase are discussed.View full abstractDownload PDF (568K) -
Eiko Sugiyama, Kei-ichi Uemura, Atsushi Hara, Tamotsu Taketomi1993 Volume 113 Issue 4 Pages 467-472
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSExogenous sphingosylphosphocholine analogues and naturally occurring sphingomyelin stimulated the neurite outgrowth in cultured murine neuroblastoma cell lines, NS-20Y, Neuro2a, and N1E-115, whereas exogenous sphinganine at a non-cytotoxic concentration inhibited the neurite outgrowth in NS-20Y and Neuro2a cells. The effect of sphingosylphos-phocholine on the neurite outgrowth was reversible, indicating that the extended neurites needed to be maintained by continuous stimulation. The uptake and metabolism of the exogenous [3-3H] sphingosylphosphocholine in pulse and chase experiments suggested that the radioactive ceramide and sphingomyelin, which were detected as major metabolic products, were in a precursor/product relationship. It is thus assumed that the exogenous sphingosylphosphocholine taken up by the cells is first degraded into phosphocholine and sphingosine, of which the latter is rapidly acylated to ceramide then converted to sphin-gomyelin by phosphocholine transfer. Metabolism of sphingosylphosphocholine through sphingomyelin synthesis in the cells may be associated with neurite outgrowth.View full abstractDownload PDF (2841K) -
Hiroyuki Takeya, Shinji Nishida, Norikazu Nishino, Yuichi Makinose, Ta ...1993 Volume 113 Issue 4 Pages 473-483
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA hemorrhagic protein (60 kDa), HR1B, present in the venom of Trimeresurus flavoviridis is a mosaic protein consisting of an NH2-terminal metalloproteinase-domain, a disintegrin (platelet aggregation inhibitor)-like domain, and a unique COOH-terminal Cys-rich domain. Since the gross structures of HR1B and protein precursors of disintegrins, trigramin, and rhodostomin, all of which contain the metalloproteinase domain, are similar, many disintegrins so far detected in snake venoms are assumed to be autoproteolytic fragments released from precursors. In ongoing related experiments, the newly purified hemorrhagic metalloproteinases, HR1A from T. flavoviridis venom and HT-1 from Crotalus ruber ruber venom, in addition to HR1B, were autoproteolyzed, in the absence of Ca2+, at 37°C for 3-12h. Under these conditions, HR1A, HR1B, and HT-1 each released a single major fragment of 32, 34, and 31 kDa, respectively. The entire amino acid sequences of the isolated fragments indicated the presence of disintegrin-like and Cys-rich domains in the COOH-terminal regions of HR1A, HR1B, and HT-1, respectively. It seems likely that so-called disintegrins probably originate from various metalloproteinases present in venom. On the bases of peptide sequences close to the autoproteolytic cleavage sites of these metalloproteinases and the sites of fibrinogen cleaved by these enzymes, we synthesized new intramolecularly quenched fluorogenic peptide substrates. Among the 10 peptides tested, 2-aminobenzoyl (Abz)-Ser-Pro-Met-Leu-2, 4-dinitroanilinoethylamide (Dna) proved to be the best substrate for venom metalloproteinase, as deduced from kinetic analyses.View full abstractDownload PDF (3291K) -
Nam-Ho Choi-Miura, Terufumi Sakamoto, Takashi Tobe, Yasuko Nakano, Mot ...1993 Volume 113 Issue 4 Pages 484-487
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSSoluble membrane attack complex (SMAC, SC5b-9) of complement contained apolipoprotein A-I (apo A-I) and lipids. Since SC5b-9 contained no apolipoprotein A-II (apo A-II), the incorporation of apo A-I and lipids into SC5b-9 was not caused by a non-specific binding of high-density lipoprotein (HDL). The incorporation of apo A-I into SC5b-9 was confirmed by a double agar diffusion immuno-assay. SC5b-9 contained one molecule of apo A-I and 3.5% lipids by weight. The composition of the lipids was phospholipid: total cholesterol: triglyceride=47.5:45.0:7.5, and the ratio of free cholesterol: esterified cholesterol was 22.3:77.7. Since SC5b-7 contained apo A-I and SC5b-9 free of SP-40, 40 contained no apo A-I, the HDL consisting of SP-40, 40, apo A-I, and lipids was incorporated into SMAC at the stage of SC5b-7 via SP-40, 40 as a binding site.View full abstractDownload PDF (2886K) -
Yuko Yuyama, Kunyama Yoshimatsu, Eriko Ono, Masayuki Saito, Masaharu N ...1993 Volume 113 Issue 4 Pages 488-492
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSEnterotoxigenic Escherichia coli possessing K 99 fimbriae (E. coli K 99) causes diarrhea in piglets of less than 1 week old. The first stage of the bacterial infection is adhesion by the fimbriae on the small intestinal mucosa and the adhesion is followed by colony formation. K 99 fimbriae bind specifically to N-glycolylneuraminyl-lactosyl-ceramide, GM3 (NeuGc) [Ono, E. et al. (1989) Infect. Immun. 57, 907-911]. We examined the postnatal change of the content and the molecular species of GM3 (NeuGc) in the small intestinal mucosa of 0- to 14-day-old piglets and adult pigs. GM3 (NeuGc) was a major ganglioside of piglet intestinal mucosa. GM3 (NeuGc) content was maximal at birth and gradually decreased to 1/16 in adult animals (5 months old). The ceramide moiety of piglet intestinal GM3 (NeuGc) was characterized by the presence of 2-hydroxylated palmitic acid. 125I-labeled bacteria strongly bound to GM3 (NeuGc) containing 2-hydroxylated palmitic acid and phytosphingosine compared with GM3 (NeuGc) containing any other ceramide moiety. The time when this particular GM3 (NeuGc) appears coincides with the time that the infection occurs, and it may explain the susceptibility of newborn piglets to E. coli K 99 infection.View full abstractDownload PDF (2719K) -
Yuji Nishizawa, Jun Uematsu, Katsushi Owaribe1993 Volume 113 Issue 4 Pages 493-501
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSHemidesmosomes (HDs) constitute a major cellular apparatus for substratum adhesion in stratified and complex epithelia. A large number of components participate in their construction. HD4, a 180 kDa polypeptide, which is one of the major constituents of the isolated HD fraction, has been suggested to be a glycoprotein, is probably identical to the 180 kDa bullous pemphigoid (BP) antigen [Owaribe, K., Nishizawa, Y., & Franke, W. W. (1991) Exp. Cell Res. 192, 622-630]. By using a sensitive method for detection of glyco-proteins, HD4 was confirmed to be a major glycoprotein in cytoskeletal fractions of certain cultured epithelial cells as well as in the HD fraction. To further characterize HD4, we prepared two groups of monoclonal antibodies (mAbs), one recognizing extracellular parts of the HD4 molecule (group I) and the other recognizing intracellular ones (group II). In cultured keratinocytes, type I mAbs, as well as BP autoantibodies that recognize both 230 and 180 kDa polypeptides, stained living cells while type II mAbs did not. The two mAbs exhibited identical staining patterns in fixed cells. HD4 molecules proved partially susceptible to collagenase and Dispase digestion, which removed epitopes of type I mAbs but not those of type II. Immunoelectron microscopy revealed the epitopes of group I mAbs to be localized in the extracellular region of HDs, whereas those of group II were on the cytoplasmic side. These results indicate that the HD4 (BP180) molecule is a major trans-membrane glycoprotein with collagen domains in its extracellular portion.View full abstractDownload PDF (6217K) -
Hatsue Waki, Akane Murata, Kazuo Kon, Kazuaki Maruyama, Shoji Kimura, ...1993 Volume 113 Issue 4 Pages 502-507
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAn O-acetylated ganglioside that generated a trisialyllactosylceramide or GT 3 by base treatment was found for the first time in cod fish brain. This ganglioside was isolated by high-performance liquid chromatography, and characterized by fast atom bombardment mass spectrometry, and proton nuclear magnetic resonance spectroscopy in addition to chemical analysis. The structure was identified as a modified GT 3 in which the external sialic acid is O-acetylated at the C-9 position. The chemical structure is as follows:
II3(9-O-Ac-NeuAc 2-8 NeuAc 2-8 NeuAc 2-3) Lac Cer.View full abstractDownload PDF (2467K) -
Setsuo Furuyoshi, Kazunori Okuyama, Masatsugu Nagatsuka, Nariyoshi Kaw ...1993 Volume 113 Issue 4 Pages 508-512
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSStannum has been found to be an essential ultratrace element, however, the biological functions of stannum remain to be clarified. We found that stannum (IV) chloride stimu-lates vanadium (IV) catalyzed free radical chain oxidation of NADH. Stannum (IV) chloride, per se, did not catalyze the NADH oxidation. Superoxide, H2O2, and OH• are known to be the key species in vanadium catalyzed NADH oxidation. The inhibition of the vanadium (IV) catalyzed NADH oxidation in the presence of stannum (IV) chloride by catalase, superoxide dismutase (SOD), and hydroxyl radical scavengers indicated that the stannum (IV) chloride stimulated NADH oxidation consisted of almost the same reaction steps as that in the absence of stannum (IV) chloride. The results of inhibition studies on the NADH oxidation with SOD and catalase suggested that the reaction mixture containing stannum (IV) chloride contained a greater amount of H2O2 and a lower amount of O2- than that containing only vanadium (IV). Hydrogen peroxide is the precursor of OH• in the free radical chain reaction. The stimulation of NADH oxidation by stannum (IV) chloride is due to the stimulation of H atom abstraction by OH•. Stannum (IV) chloride might stimulate the generation of OH• by producing H2O2.View full abstractDownload PDF (520K) -
Yakeo Yamaguchi, Kazuhiro Kuranoshita, Takuji Harano, Eiji Kimoto1993 Volume 113 Issue 4 Pages 513-518
Published: April 01, 1993
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSWhen human erythrocytes subjected to a pressure of 2.0 kbar were incubated at 0°C and atmospheric pressure, hemoglobin was released from the membrane. Effects of drugs, salts, and phospholipid vesicles on hemoglobin release were examined. The hemoglobin release was suppressed by the addition of amphipathic drugs such as chlorpromazine, trifluoper-azine, tetracaine, indomethacin, and phenylbutazone or by a hypertonic condition. The suppressive effect induced by these drugs or hypertonic buffer was enhanced by the addition of aminophospholipid vesicles containing phosphatidylserine (PS) and/or phos-phatidylethanolamine (PE) but decreased by vesicles composed of phosphatidylcholine (PC) and sphingomyelin. In the isotonic buffer without these drugs, such effects of vesicles were small. The suppressive effects of PS and PE were decreased by chemical modification of carboxylic groups and amino groups with 1-ethyl-3-(3-dimethylaminopropyl)carbodi-imide and 2, 4, 6-trinitrobenzenesulfonate, respectively. The size of vesicles as well as phospholipid composition was also an important factor in the suppression of hemoglobin release. The ESR spectrum of pressure-treated membrane spin-labeled with a maleimide was changed by PC vesicles but not by PS vesicles. These results indicate that the resealing of pressure-induced membrane holes by amphipathic drugs or hypertonic medium is synergistic with aminophospholipid vesicles and the hole size is affected by the vesicle-membrane protein interaction.View full abstractDownload PDF (736K)
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