Matches in SemOpenAlex for { <https://semopenalex.org/work/W2079967695> ?p ?o ?g. }
- W2079967695 endingPage "3497" @default.
- W2079967695 startingPage "3488" @default.
- W2079967695 abstract "TP40 is a chimeric protein containing transforming growth factor alpha (TGF-alpha) at the N-terminus and a derivative of a 40,000-Da segment (PE40 delta cys) of Pseudomonas exotoxin (PE). PE40 delta cys contains domains Ib, II, and III of PE in which the cysteines are mutated to alanines. The rationale for inclusion of TGF-alpha is to provide TP40 with selective targeting toward cells expressing the epidermal growth factor receptor (EGFr) on their surface [Pastan, I., & FitzGerald, D. (1989) J. Biol. Chem. 264, 15157-15160]. Translocation across endosomal membranes is thought to be a required step for cytotoxic activity of PE. This step is presumably facilitated by the low pH in endosomes which induces exposure of a hydrophobic surface of the protein, which in turn becomes available to interact with and translocate across the membrane. We have employed the hydrophobic fluorescence probe 2-p-toludinylnaphthalene-6-sulfonate (TNS) and the intrinsic tryptophan fluorophores of TP40 to investigate pH-induced changes in the tertiary structure of this protein. The pH dependence of TP40 interaction with liposomes also provided a model for studying protein-membrane interactions. TNS fluorescence was markedly enhanced in the presence of TP40 below pH 4 and to a lesser degree between pH 7 and 5. A progressive red shift of tryptophan fluorescence with decreasing pH was also seen with the approximate midpoint for this transition occurring around pH 3. Both observations suggest that acidic pH induces exposure of hydrophobic regions of TP40, making them accessible to solvent and TNS. No major alteration of the secondary structure was manifested in the far-UV CD spectrum of TP40 upon a reduction in pH from 7 to 2. Thus, the low-pH-induced structural change of TP40 appears to involve a subtle exposure of one or more hydrophobic surfaces without an extensive unfolding of the protein's secondary structure. In the presence of anionic liposomes, a low-pH-induced blue shift of the TP40 tryptophan fluorescence was observed, suggesting that interaction with liposomes also required the low-pH conformation of the protein. However, the midpoint of this fluorescence blue shift occurred at approximately pH 5, which is presumably closer to the physiological pH within endosomes. Neutral liposomes failed to induce these spectral changes in TP40, implying a lack of interaction with these lipids. At acidic pH values between 2 and 4, self-association of TP40 in solution was detected by equilibrium sedimentation and quasielastic light scattering measurements. This probably results from intermolecular interaction between exposed hydrophobic surfaces.(ABSTRACT TRUNCATED AT 400 WORDS)" @default.
- W2079967695 created "2016-06-24" @default.
- W2079967695 creator A5014345880 @default.
- W2079967695 creator A5060120854 @default.
- W2079967695 creator A5074232195 @default.
- W2079967695 creator A5090481795 @default.
- W2079967695 date "1993-04-01" @default.
- W2079967695 modified "2023-09-27" @default.
- W2079967695 title "A transforming growth factor-.alpha.-Pseudomonas exotoxin hybrid protein undergoing pH-dependent conformational changes conducive to membrane interaction" @default.
- W2079967695 cites W1484985322 @default.
- W2079967695 cites W1486259053 @default.
- W2079967695 cites W1544273108 @default.
- W2079967695 cites W1561227425 @default.
- W2079967695 cites W1568036284 @default.
- W2079967695 cites W1568217878 @default.
- W2079967695 cites W1585310162 @default.
- W2079967695 cites W1588613452 @default.
- W2079967695 cites W1602413288 @default.
- W2079967695 cites W182610081 @default.
- W2079967695 cites W1871697173 @default.
- W2079967695 cites W1894050938 @default.
- W2079967695 cites W1901281796 @default.
- W2079967695 cites W1981147325 @default.
- W2079967695 cites W1984766041 @default.
- W2079967695 cites W1998329643 @default.
- W2079967695 cites W2012330612 @default.
- W2079967695 cites W2014335282 @default.
- W2079967695 cites W2016453061 @default.
- W2079967695 cites W2024908512 @default.
- W2079967695 cites W2026401160 @default.
- W2079967695 cites W2027339215 @default.
- W2079967695 cites W2035544432 @default.
- W2079967695 cites W2035595494 @default.
- W2079967695 cites W2036895460 @default.
- W2079967695 cites W2040286733 @default.
- W2079967695 cites W2044569715 @default.
- W2079967695 cites W2053483740 @default.
- W2079967695 cites W2054983719 @default.
- W2079967695 cites W2057609017 @default.
- W2079967695 cites W2060295808 @default.
- W2079967695 cites W2062228103 @default.
- W2079967695 cites W2069520354 @default.
- W2079967695 cites W2071224136 @default.
- W2079967695 cites W2072767834 @default.
- W2079967695 cites W2084499159 @default.
- W2079967695 cites W2088107416 @default.
- W2079967695 cites W2096490954 @default.
- W2079967695 cites W2103161626 @default.
- W2079967695 cites W2107276905 @default.
- W2079967695 cites W2128545518 @default.
- W2079967695 cites W2130012375 @default.
- W2079967695 cites W2135826089 @default.
- W2079967695 cites W2137333901 @default.
- W2079967695 cites W2137747032 @default.
- W2079967695 cites W2177651721 @default.
- W2079967695 cites W2212272536 @default.
- W2079967695 cites W4247078028 @default.
- W2079967695 doi "https://doi.org/10.1021/bi00064a037" @default.
- W2079967695 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/8461310" @default.
- W2079967695 hasPublicationYear "1993" @default.
- W2079967695 type Work @default.
- W2079967695 sameAs 2079967695 @default.
- W2079967695 citedByCount "11" @default.
- W2079967695 crossrefType "journal-article" @default.
- W2079967695 hasAuthorship W2079967695A5014345880 @default.
- W2079967695 hasAuthorship W2079967695A5060120854 @default.
- W2079967695 hasAuthorship W2079967695A5074232195 @default.
- W2079967695 hasAuthorship W2079967695A5090481795 @default.
- W2079967695 hasConcept C102747710 @default.
- W2079967695 hasConcept C109316439 @default.
- W2079967695 hasConcept C121332964 @default.
- W2079967695 hasConcept C12554922 @default.
- W2079967695 hasConcept C125555471 @default.
- W2079967695 hasConcept C170493617 @default.
- W2079967695 hasConcept C182179738 @default.
- W2079967695 hasConcept C185592680 @default.
- W2079967695 hasConcept C202751555 @default.
- W2079967695 hasConcept C2776362946 @default.
- W2079967695 hasConcept C2776706248 @default.
- W2079967695 hasConcept C41625074 @default.
- W2079967695 hasConcept C515207424 @default.
- W2079967695 hasConcept C55493867 @default.
- W2079967695 hasConcept C62520636 @default.
- W2079967695 hasConcept C86803240 @default.
- W2079967695 hasConcept C90260826 @default.
- W2079967695 hasConcept C91881484 @default.
- W2079967695 hasConceptScore W2079967695C102747710 @default.
- W2079967695 hasConceptScore W2079967695C109316439 @default.
- W2079967695 hasConceptScore W2079967695C121332964 @default.
- W2079967695 hasConceptScore W2079967695C12554922 @default.
- W2079967695 hasConceptScore W2079967695C125555471 @default.
- W2079967695 hasConceptScore W2079967695C170493617 @default.
- W2079967695 hasConceptScore W2079967695C182179738 @default.
- W2079967695 hasConceptScore W2079967695C185592680 @default.
- W2079967695 hasConceptScore W2079967695C202751555 @default.
- W2079967695 hasConceptScore W2079967695C2776362946 @default.
- W2079967695 hasConceptScore W2079967695C2776706248 @default.
- W2079967695 hasConceptScore W2079967695C41625074 @default.