A complex high molecular mass non-lysosomal proteinase of mammalian cells

1988 ◽  
Vol 16 (4) ◽  
pp. 629-630
Author(s):  
A. JENNIFER RIVETT
1989 ◽  
Vol 259 (2) ◽  
pp. 549-553 ◽  
Author(s):  
J Szelei ◽  
E Duda

We modified the Ca/EDTA procedure for the production of liposomes [Papahadjopoulos, Vail, Jacobson & Poste (1975) Biochim. Biophys. Acta 394, 483-491] to entrap intact DNA molecules of very high molecular mass into large unilamellar phospholipid vesicles. The use of DNA-protein complexes and phage particles instead of naked linear DNA increases the efficiency of entrapment and protects the integrity of DNA molecules. We investigated the interaction of mammalian cells with liposome-encapsulated recombinant lambda bacteriophages carrying marker genes. The liposomes bind surprisingly fast to the cellular surface and are taken up by the cells. A significant proportion of the encapsulated DNA is transported to and soon located in or around the nuclei. Experiments prove that these liposomes can be used for the genetic transformation of mammalian cells.


2001 ◽  
Vol 2 (6) ◽  
pp. 371-377 ◽  
Author(s):  
Tarek E Selim ◽  
Hayam R Ghoneim ◽  
Hassan A Abdel Ghaffar ◽  
Robert W Colman ◽  
Raul A Dela Cadena

Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 453
Author(s):  
Sebastian Estrada-Gómez ◽  
Leidy Johana Vargas-Muñoz ◽  
Cesar Segura Latorre ◽  
Monica Maria Saldarriaga-Cordoba ◽  
Claudia Marcela Arenas-Gómez

Nowadays, spider venom research focuses on the neurotoxic activity of small peptides. In this study, we investigated high-molecular-mass compounds that have either enzymatic activity or housekeeping functions present in either the venom gland or venom of Pamphobeteus verdolaga. We used proteomic and transcriptomic-assisted approaches to recognize the proteins sequences related to high-molecular-mass compounds present in either venom gland or venom. We report the amino acid sequences (partial or complete) of 45 high-molecular-mass compounds detected by transcriptomics showing similarity to other proteins with either enzymatic activity (i.e., phospholipases A2, kunitz-type, hyaluronidases, and sphingomyelinase D) or housekeeping functions involved in the signaling process, glucanotransferase function, and beta-N-acetylglucosaminidase activity. MS/MS analysis showed fragments exhibiting a resemblance similarity with different sequences detected by transcriptomics corresponding to sphingomyelinase D, hyaluronidase, lycotoxins, cysteine-rich secretory proteins, and kunitz-type serine protease inhibitors, among others. Additionally, we report a probably new protein sequence corresponding to the lycotoxin family detected by transcriptomics. The phylogeny analysis suggested that P. verdolaga includes a basal protein that underwent a duplication event that gave origin to the lycotoxin proteins reported for Lycosa sp. This approach allows proposing an evolutionary relationship of high-molecular-mass proteins among P. verdolaga and other spider species.


2002 ◽  
Vol 366 (2) ◽  
pp. 511-520 ◽  
Author(s):  
Benjamin L. SCHULZ ◽  
David OXLEY ◽  
Nicolle H. PACKER ◽  
Niclas G. KARLSSON

Human open eye tear fluid was separated by low-percentage SDS/PAGE to detect high-molecular-mass protein components. Two bands were found with apparent molecular masses of 330 and 270kDa respectively. By peptide-mass fingerprinting after tryptic digestion, the proteins were found to be isoforms of the DMBT1 gene product, with over 30% of the predicted protein covered by the tryptic peptides. By using gradient SDS/agarose/polyacrylamide composite gel electrophoresis and staining for glycosylation, it was shown that the two isoforms were the major high-molecular-mass glycoproteins of >200kDa in human tear fluid. Western blotting showed that the proteins expressed sialyl-Lea. After the release of oligosaccharides by reductive β-elimination from protein blotted on to PVDF membrane, it was revealed by liquid chromatography-MS that the O-linked oligosaccharides were comprised mainly of highly sialylated oligosaccharides with up to 16 monosaccharide units. A majority of the oligosaccharides could be described by the formula dHex0→2NeuAc1→xHexxHexNAcx(-ol), x = 1–6, where Hex stands for hexose, dHex for deoxyhexose, HexNAc for N-acetylhexosamine and NeuAc for N-acetylneuraminate. The number of sialic acids in the formula is less than 5. Interpretation of collision-induced fragmentation tandem MS confirmed the presence of sialic acid and suggested the presence of previously undescribed structures carrying the sialyl-Lea epitopes. Small amounts of neutral and sulphated species were also present. This is the first time that O-linked oligosaccharides have been detected and described from protein variant of the DMBT1 gene.


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