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J Schnabel

Publications and source records attributed to J Schnabel.

6 recordsLinked to original sources
PubMed1998

Protein-protein interactions between keratin polypeptides expressed in the yeast two-hybrid system.

Keratin filaments are obligatory heteropolymers of type I and type II keratin polypeptides. Specific type I/type II pairs are coexpressed in vivo. In contrast, all type I/type II pairs assemble into filaments in vitro, but the different pairs have different stabilities as demonstrated by treatment with increasing concentrations of urea. We have used the yeast two-hybrid system to analyse type I/type II interactions in a cellular context. We measured interactions between two different keratin pairs and we confirm the findings that K6+K17 form very stable heterodimers whereas K8+K18 interactions were weaker. The deletion of head domains did not reduce the strength of type I/type II interactions. Rather, the affinities were increased and the differences between the two pairs were retained in headless mutants. These findings argue against a major role of the head domains in directing heterodimer interactions and in defining heterodimer stabilities.

Intermediate Filaments↗
PubMed1995

Dubious alliance.

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Drug Approval↗
PubMed1992

Postinjury scopolamine administration in experimental traumatic brain injury.

A single bolus dose of scopolamine (1.0 mg/kg) or saline (equal volume) was injected (i.p.) at 15, 30 or 60 min after fluid percussion traumatic brain injury in the rat. Scopolamine administered at 15 min postinjury significantly reduced beam walking deficits and body weight loss assessed for 5 days after injury. Scopolamine treatment at 30 or 60 min postinjury had no effect on behavioral outcome assessed for 5 days after injury. Plasma concentrations of scopolamine were measured with a radioreceptor assay. The plasma half-life for scopolamine was 21.6 min in injured rats and 17.3 min in normal rats (P less than 0.05). These results, along with evidence from previous studies, suggest that a brief period of excessive neuronal excitation can produce relatively long-lasting behavioral deficits. The temporal effectiveness of receptor antagonist intervention in this process appears to be brief.

Animals↗
PubMed1991

Cholesterol-transfer protein located in the intestinal brush-border membrane. Partial purification and characterization.

Cholesterol absorption by small intestinal brush border membrane vesicles from taurocholate mixed micelles is a second-order reaction. From a comparison of reaction rates and order before and after proteinase K treatment of brush-border membrane vesicles, it is concluded that cholesterol absorption is protein-mediated. It is shown that the desorption of cholesterol from taurocholate mixed micelles is by a factor of about 10(4) faster than that from egg phosphatidylcholine bilayers. When brush border membrane vesicles are stored at room temperature, intrinsic proteinases are activated and proteins are liberated from the brush border membrane. These proteins collected in the supernatant catalyze cholesterol and phosphatidylcholine exchange between two populations of small unilamellar phospholipid vesicles. One of the active proteins present in the supernatant is purified by a two-step procedure involving gel filtration on Sephadex G-75 SF and affinity chromatography on a Nucleosil-phosphatidylcholine column. The protein thus obtained is pure by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. It has an apparent molecular weight of slightly less than 14,000 as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis and a value of 11,500 determined by gel filtration on Sephadex G-75 SF.

Animals↗