Our previous studies showed a predominance of high molecular weight protein group in tumor nuclear matrices. contrary to normal cells, Proteins of this group are Preferentially phosphorylated. Phosphoproteins of hepat...Our previous studies showed a predominance of high molecular weight protein group in tumor nuclear matrices. contrary to normal cells, Proteins of this group are Preferentially phosphorylated. Phosphoproteins of hepatoma nuclear matrix are selectively subjected to rapid proteolysis. By alkali treatment and a monoclonal antibody against phosphotyrosyl residue the presence of two high molecular weight bands of phosphotyrosyl-containing proteins was defected in nuclear matrices of tumor but not of normal liver cells. High molecular weight protein group of tumor nuclear matrices revealed also a rapid turnover and preferential incorporation of labeled amino acids selectively inhibited by chioramphenicol.展开更多
Lentinan samples, (1→3)-β-D-glucans containing 4.6-15.2 wt% proteins, coded as L-I1, L-I2, L-I3 and L-I4 (L-I)were isolated from four kinds of Lentinus edodes. These glucans were treated with acetone to remove the p...Lentinan samples, (1→3)-β-D-glucans containing 4.6-15.2 wt% proteins, coded as L-I1, L-I2, L-I3 and L-I4 (L-I)were isolated from four kinds of Lentinus edodes. These glucans were treated with acetone to remove the protein in order to obtain free protein glucans coded as LNP-I1, LNP-I2, LNP-I3 and LNP-I4 (LNP-I). The free-protein polysaccharides were sulfated to give derivatives (S-LNP-I) with degree of substitution (DS) from 0.4-0.8. The structural features and weight- average molecular weight (Mw) of the samples were investigated by using infrared spectroscopy, elemental analysis,13C-NMR, size exclusion chromatography combined with laser light scattering (SEC-LLS) and viscometry. The effects of structure and conformation of the polysaccharides on antitumor activities were assayed in vivo (Sarcoma 180 solid tumors)and in vitro (Sarcoma 180, HL-60, MCF-7 and Vero tumors). The results indicated that the predominant species of the samples L-I and LNP-I in 0.2 mol/L NaCl aqueous solution existed as triple-helical chains with high rigidity and in dimethyl sulfoxide (DMSO) as single-flexible chains. Interestingly, the antitumor activities of LNP-I are lower than those of the native glucans (L-I), whereas their sulfated derivatives have higher inhibition ratio against Sarcoma 180 than LNP-I. The results reveal that the binding of protein, sulfated modification and the triple helix conformation are important factors in the enhancement of the antitumor activities of polysaccharides on the whole.展开更多
An improved CBB staining with higher sensitivity than that of the typical CBB staining was reported.The main improvement was using a fixing step of 25% trichloroacetic acid(TCA) before CBB staining.For most proteins s...An improved CBB staining with higher sensitivity than that of the typical CBB staining was reported.The main improvement was using a fixing step of 25% trichloroacetic acid(TCA) before CBB staining.For most proteins studied,the sensitivity of the improved CBB staining was about twice as high as that of the typical method.For basic and low molecular weight proteins such as ribosomal proteins,the sensitivity of this improved staining method was about 3.5-28 times that of the typical method.It was speculated that the improved procedure would be suitable for exact quantitative analysis of proteins fractionated by SDS-PAGE,especially for basic and low molecular weight proteins.On the other hand,this new modified method might be also applied to multidisciplinary studies,such as biological researches and nuclear sciences.展开更多
AIM: To study HCV polyprotein processing is important forthe understanding of the natural history of HCV and thedesign of vaccines against HCV. The purpose of this studyis to investigate the affection of context seque...AIM: To study HCV polyprotein processing is important forthe understanding of the natural history of HCV and thedesign of vaccines against HCV. The purpose of this studyis to investigate the affection of context sequences onhepatitis C virus (HCV) E2 processingMETHODS: HCV genes of different lengths were expressedand compared in vaccinia virus/T7 system with homologouspatient serum S94 and mouse anti-serum ME2116 raisedagainst E. coli-derived E2 peptide, respectively.Deglycosylation analysis and GNA (Galanthus nivalus )lectin binding assay were performed to study the post-translational processing of the expressed products.RESULTS: E2 glycoproteins with different molecular weights( ～ 75kDa end ～ 60kDa) were detected using S94 and ME2116,respectively. Deglycosylation analysis showed that thisdifference was mainly due to different glycosylation. Endo Hresistance and its failure to bind to GNA lectin demonstratedthat the higher molecular weight form (75kDa) of E2 wascomplex-type glycosylated, which was readily recognized byhomologous patient serum S94. Expression of complex-typeglycosylated E2 could not be detected in all of the core-truncated constructs tested, but readily detected inconstructs encoding full-length core sequences.CONCLUSION: The upstream conserved full-length corecoding sequence was required for the production of E2glycoproteins carrying complex-type N-glycans whichreacted strongly with homologous patient serum andtherefore possibly represented more mature forms of E2. Ascomplex-type N-glycans indicated modification by Golgienzymes, the results suggest that the presence of full-lengthcore might be critical for E1/E2 complex to leave ER. Ourdata may contribute to a better understanding of theprocessing of HCV structural proteins as well as HCVmorphogenesis.展开更多
We introduce a new method for separation/enrichment of the low-content cellular protein in high mo-lecular weight on the basis of molecular imprinting. The template protein, bacterial cloned immu-noglobulin binding pr...We introduce a new method for separation/enrichment of the low-content cellular protein in high mo-lecular weight on the basis of molecular imprinting. The template protein, bacterial cloned immu-noglobulin binding protein (BiP), was selectively assembled with assistant recognition polymer chains (ARPCs) from their library, which consists of numerous limited length polymer chains with randomly distributed recognition and immobilizing sites. The assemblies of proteins and ARPCs were adsorbed by porous polymeric beads and immobilized by cross-linking polymerization. After the template was removed, the synthesized imprinted polymer was used to adsorb authentic BiP from endoplasmic re-ticulum (ER) extract, and its proportional content was enriched 45 times. It is the first time that the low-content cellular natural protein, whose molecular weight reaches 78 kDa, is enriched by molecular imprinting.展开更多
Matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI/MS) is a new, powerful analytical tool for the investigation of large biomolecules. Since its inception in 1986 by Koichi Tanaka and ...Matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI/MS) is a new, powerful analytical tool for the investigation of large biomolecules. Since its inception in 1986 by Koichi Tanaka and Franz Hillenkamp separately, MALDI/MS has been successfully applied to the investigation of展开更多
文摘Our previous studies showed a predominance of high molecular weight protein group in tumor nuclear matrices. contrary to normal cells, Proteins of this group are Preferentially phosphorylated. Phosphoproteins of hepatoma nuclear matrix are selectively subjected to rapid proteolysis. By alkali treatment and a monoclonal antibody against phosphotyrosyl residue the presence of two high molecular weight bands of phosphotyrosyl-containing proteins was defected in nuclear matrices of tumor but not of normal liver cells. High molecular weight protein group of tumor nuclear matrices revealed also a rapid turnover and preferential incorporation of labeled amino acids selectively inhibited by chioramphenicol.
基金This work was supported by the National Natural Science Foundation of China(No.20074025).
文摘Lentinan samples, (1→3)-β-D-glucans containing 4.6-15.2 wt% proteins, coded as L-I1, L-I2, L-I3 and L-I4 (L-I)were isolated from four kinds of Lentinus edodes. These glucans were treated with acetone to remove the protein in order to obtain free protein glucans coded as LNP-I1, LNP-I2, LNP-I3 and LNP-I4 (LNP-I). The free-protein polysaccharides were sulfated to give derivatives (S-LNP-I) with degree of substitution (DS) from 0.4-0.8. The structural features and weight- average molecular weight (Mw) of the samples were investigated by using infrared spectroscopy, elemental analysis,13C-NMR, size exclusion chromatography combined with laser light scattering (SEC-LLS) and viscometry. The effects of structure and conformation of the polysaccharides on antitumor activities were assayed in vivo (Sarcoma 180 solid tumors)and in vitro (Sarcoma 180, HL-60, MCF-7 and Vero tumors). The results indicated that the predominant species of the samples L-I and LNP-I in 0.2 mol/L NaCl aqueous solution existed as triple-helical chains with high rigidity and in dimethyl sulfoxide (DMSO) as single-flexible chains. Interestingly, the antitumor activities of LNP-I are lower than those of the native glucans (L-I), whereas their sulfated derivatives have higher inhibition ratio against Sarcoma 180 than LNP-I. The results reveal that the binding of protein, sulfated modification and the triple helix conformation are important factors in the enhancement of the antitumor activities of polysaccharides on the whole.
文摘An improved CBB staining with higher sensitivity than that of the typical CBB staining was reported.The main improvement was using a fixing step of 25% trichloroacetic acid(TCA) before CBB staining.For most proteins studied,the sensitivity of the improved CBB staining was about twice as high as that of the typical method.For basic and low molecular weight proteins such as ribosomal proteins,the sensitivity of this improved staining method was about 3.5-28 times that of the typical method.It was speculated that the improved procedure would be suitable for exact quantitative analysis of proteins fractionated by SDS-PAGE,especially for basic and low molecular weight proteins.On the other hand,this new modified method might be also applied to multidisciplinary studies,such as biological researches and nuclear sciences.
基金the National 863 High Technology Foundation of China,No.863-102-07-02-02,No.2001AA215171the project CHN 98/112 (WTZ-Internationales Buro des BMBF).
文摘AIM: To study HCV polyprotein processing is important forthe understanding of the natural history of HCV and thedesign of vaccines against HCV. The purpose of this studyis to investigate the affection of context sequences onhepatitis C virus (HCV) E2 processingMETHODS: HCV genes of different lengths were expressedand compared in vaccinia virus/T7 system with homologouspatient serum S94 and mouse anti-serum ME2116 raisedagainst E. coli-derived E2 peptide, respectively.Deglycosylation analysis and GNA (Galanthus nivalus )lectin binding assay were performed to study the post-translational processing of the expressed products.RESULTS: E2 glycoproteins with different molecular weights( ～ 75kDa end ～ 60kDa) were detected using S94 and ME2116,respectively. Deglycosylation analysis showed that thisdifference was mainly due to different glycosylation. Endo Hresistance and its failure to bind to GNA lectin demonstratedthat the higher molecular weight form (75kDa) of E2 wascomplex-type glycosylated, which was readily recognized byhomologous patient serum S94. Expression of complex-typeglycosylated E2 could not be detected in all of the core-truncated constructs tested, but readily detected inconstructs encoding full-length core sequences.CONCLUSION: The upstream conserved full-length corecoding sequence was required for the production of E2glycoproteins carrying complex-type N-glycans whichreacted strongly with homologous patient serum andtherefore possibly represented more mature forms of E2. Ascomplex-type N-glycans indicated modification by Golgienzymes, the results suggest that the presence of full-lengthcore might be critical for E1/E2 complex to leave ER. Ourdata may contribute to a better understanding of theprocessing of HCV structural proteins as well as HCVmorphogenesis.
基金Supported by the National Natural Science Foundation of China (Grant No. 20674040)
文摘We introduce a new method for separation/enrichment of the low-content cellular protein in high mo-lecular weight on the basis of molecular imprinting. The template protein, bacterial cloned immu-noglobulin binding protein (BiP), was selectively assembled with assistant recognition polymer chains (ARPCs) from their library, which consists of numerous limited length polymer chains with randomly distributed recognition and immobilizing sites. The assemblies of proteins and ARPCs were adsorbed by porous polymeric beads and immobilized by cross-linking polymerization. After the template was removed, the synthesized imprinted polymer was used to adsorb authentic BiP from endoplasmic re-ticulum (ER) extract, and its proportional content was enriched 45 times. It is the first time that the low-content cellular natural protein, whose molecular weight reaches 78 kDa, is enriched by molecular imprinting.
文摘Matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI/MS) is a new, powerful analytical tool for the investigation of large biomolecules. Since its inception in 1986 by Koichi Tanaka and Franz Hillenkamp separately, MALDI/MS has been successfully applied to the investigation of
