Biomedical subjects

J Juul

Publications and source records attributed to J Juul.

16 recordsLinked to original sources

PubMed1996

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and centrifuge blotting: preparation of polypeptides for amino-terminal sequence analysis.

The applicability and reproducibility of a previously described (L. F. Hermansen et al., Electrophoresis 1993, 14, 1302-1306) centrifuge-blotting procedure for capturing subnanomolar amounts of protein on polyvinylidene difluoride membranes for direct Edman degradation was further investigated. Proteins with different molecular masses were centrifuge-blotted onto Immobilon CD membranes. Simultaneous blotting and desalting was achieved with an overall yield of 15-56% after 2 h centrifugation for proteins with a molecular mass of 12-30 kDa. Centrifugation of myoglobin for 6 h resulted in an overall yield of 72%. The subnanomolar amounts obtained were also sufficient to conduct cyanogen bromide cleavage in situ on proteins with blocked NH2-terminus and to generate sequence information.

Centrifugation↗

PubMed1995

Elucidation of the primary and three-dimensional structure of the uterotonic polypeptide kalata B1.

The amino acid sequence and structure of a uterotonic polypeptide extracted from the African plant Oldenlandia affinis DC have been determined. The peptide, kalata B1, consists of 29 amino acid residues and is rich in cysteine (6), threonine (5), and glycine (5). Enzyme cleavage studies show that the polypeptide backbone is cyclic. The three-dimensional solution structure has been determined using two-dimensional nuclear magnetic resonance (NMR) spectroscopy and distance-restrained simulated annealing. Kalata B1 is composed mainly of beta-strands connected by tight turns, forming regions of beta-sheet, except in the case of one section which forms a longer, less structured loop. The tertiary fold, together with the disulfides that form a sulfur core, produces a striking and unusual surface in which the majority of the hydrophobic residues form a solvent-exposed patch. The hydrophobic side of kalata B1 is flanked by two diametrically opposed and opposite-charged residues. The structure calculations have been used to predict the previously unknown disulfide bond connectivities using two approaches. In the first, a family of structures was calculated on the basis of NOE constraints without the assumption of a specific disulfide connectivity. The resultant structures were examined to determine whether the calculated position of the sulfur atoms suggested that one set of disulfide connectivities was more likely than the other, theoretically possible, sets. In the second approach, a separate family of structures (50 per set) was calculated for each of the 15 possible disulfide-bonded molecules. The resultant families of structures were compared to see whether one was favored over the others. Both approaches led to the same global fold, and the most likely disulfide connectivity is predicted to be 5-22, 13-27, and 17-29. In the calculated structure the cyclic peptide backbone is folded back onto itself and braced with disulfide pairs across diagonally opposed beta-strands. This structure involves one of the disulfide bonds (5-22) threading through the eight amino acid loop formed by the other two disulfide bonds and the peptide fragments connecting them.

Amino Acid Sequence↗

PubMed1994

The primary structure of serum amyloid A protein in the sheep: comparison with serum amyloid A in other species.

Serum amyloid A (SAA) protein was isolated from acute phase sheep sera by ultracentrifugation, gel filtration and ion-exchange chromatography. The purified protein was characterized by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focusing, amino acid composition and Edman degradation. Protein SAA sheep consists of 112 amino acid residues and has a blocked N-terminus. The amino acid sequence showed a high degree of homology with SAA proteins from other species, especially at positions 32 to 54, indicating that this particular part of the protein is important for its function. When compared to human protein SAA, nine inserted amino acids could be demonstrated, located in regions 69 to 77. Similar observations have been seen in cow, horse, dog, cat, and mink protein SAA. Heterogeneities were found in positions 28, 55, 63, 64, 66, 75, 77, 78, 80 and 89. Positions 63, 64, 66, 75, 77, 78 and 80 revealed the existence of a minor gene product of protein SAA sheep. The minor variant of protein SAA sheep is identical in these positions with the corresponding positions in protein SAA cow. By comparing the amino acid sequences of the different SAA proteins, two separate branches in the evolutionary pattern of protein SAA appear. One of the branches includes the species with the insertion which represents also one of the more heterogeneous part of the protein.

Acute-Phase Reaction↗

PubMed1993

The primary structure of rabbit serum amyloid A protein isolated from acute phase serum.

Serum amyloid A (SAA) protein, a sensitive acute phase protein and the precursor of protein AA in secondary amyloid, was purified from pooled acute phase rabbit serum using two different methods: isolation of protein SAA directly by octyl-Sepharose chromatography of total serum, and dissociation and isolation of apoSAA from acute phase high density lipoprotein (HDL). The protein SAA fraction obtained was further purified using gel filtration and ion exchange chromatography. Rabbit protein SAA has 104 amino acid residues, like human SAA, and has a partially blocked N terminus. The highly conserved region from position 33 to position 63 found in SAA from all species studied was confirmed also in rabbit SAA. No microheterogeneities were observed. The amino acid sequence showed extensive N-terminal homology with the rabbit amyloid A protein, except for the microheterogeneity in position 12 in protein AA. It also showed identical amino acid sequence with that deduced from the rabbit cDNA clone pSAA 55. Complete homologies were found with clone SAA 2, except for positions 22 and 78, clone SA8-1, except for positions 22 and 79 and clone SA7-3, except for position 22. This pSAA 55/SA7-3/SA8-1/SAA2-like protein was the only SAA isotype found both in total serum and in the HDL fraction. Isotypes corresponding to other SAA-like genes could not be found in this pool of acute phase rabbit sera.

Acute-Phase Reaction↗

PubMed1989

Use of subcutaneous abdominal fat biopsy specimen for detailed typing of amyloid fibril protein-AL by amino acid sequence analysis.

A simple technique for the purification of amyloid fibril proteins from patients with systemic amyloidosis was used on a 45 year old woman. The method is based on the use of a surgical subcutaneous fat tissue biopsy specimen which was used for the characterisation of the amyloid as a kappa I AL-protein by amino acid sequence analysis. The method permits the exact typing of amyloid in many patients with systemic amyloidosis, which, until now has been almost exclusively confined to necropsy tissue.

Abdomen↗

PubMed1988

Epidural analgesia vs. general anesthesia for cesarean section.

A prospective study based upon interviews included 92 women who had undergone cesarean section, 38% with epidural analgesia and 62% under general anesthesia. The two groups were compared with respect to anesthesiological complications, postoperative morbidity and birth experience. The puerperal period was less complicated after epidural analgesia than after general anesthesia. There was a quicker re-establishment of the gastrointestinal function after epidural analgesia and the patients were more quickly mobilized and less tired. The overall morbidity after cesarean section, 16%, was lower than in other studies. Nearly half of the patients in the epidural experienced slight peroperative pain. In the case of repeated cesarean section, 86% of women who had epidural analgesia wanted the same anesthesia again. On the basis of this study, epidural analgesia is recommended for cesarean section.

Anesthesia, Epidural↗

PubMed1988

Effect of epidural vs. general anesthesia on breastfeeding.

In a prospective interview study, two groups each consisting of 28 sectio caesarea patients were compared concerning the course of breastfeeding. The women in the two groups were delivered under either epidural analgesia or general anesthesia. The two groups were identical with respect to age, parity, participation in antenatal preparatory courses and former breastfeeding. A significantly higher breastfeeding frequency and longer breastfeeding periods were were found after epidural analgesia than after general anesthesia.

Anesthesia, Epidural↗

PubMed1981

The complete amino acid sequence of a prototype immunoglobulin-lambda light-chain-type amyloid-fibril protein AR.

The amino acid sequence of an amyloid-fibril protein of immunoglobulin light-chain type (AL) was elucidated. The sequence determination involved digesting the protein with trypsin, thermolysin and pepsin. The protein was found to consist of 154 amino acid residues and is thus missing about half of the constant region of a light chain. A certain heterogeneity in the length of the polypeptide was observed in the C-terminal region. The amino acid sequence from CDR (complementary-determining region) 1 and FR (framework region) 3 indicated an oligoclonal origin of the protein. By comparing the primary structure of protein AR with other lambda- and even kappa-chains, it was revealed that protein AR had an insertion of two residues of aspartic acid, namely residues 68 and 69, which has not been reported previously in light chains. The overall sequence homology in the variable region showed that protein AR is more similar to V lambda V than to the other subgroups [Kabat, Wu & Bilofsky (1979) Variable regions of Immunoglobulin Chains, Medical Computer Systems, Bolt, Beranek and Newman, Cambridge, MA].

Amino Acid Sequence↗

PubMed1974