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Biomedical subjects

R van den Broek

Publications and source records attributed to R van den Broek.

9 recordsLinked to original sources
PubMed1987

The N-terminal sequence of ribosomal protein L10 from the archaebacterium Halobacterium marismortui and its relationship to eubacterial protein L6 and other ribosomal proteins.

The amino-terminal sequence of ribosomal protein L10 from Halobacterium marismortui has been determined up to residue 54, using both a liquid- and a gas-phase sequenator. The two sequences are in good agreement. The protein is clearly homologous to protein HcuL10 from the related strain Halobacterium cutirubrum. Furthermore, a weaker but distinct homology to ribosomal protein L6 from Escherichia coli and Bacillus stearothermophilus can be detected. In addition to 7 identical amino acids in the first 36 residues in all four sequences a number of conservative replacements occurs, of mainly hydrophobic amino acids. In this common region the pattern of conserved amino acids suggests the presence of a beta-alpha fold as it occurs in ribosomal proteins L12 and L30. Furthermore, several potential cases of homology to other ribosomal components of the three ur-kingdoms have been found.

Amino Acid Sequence↗
PubMed1987

The amino acid sequence of crystalline sheets: a proteolytic fragment of the major head protein (gP23) of bacteriophage T4.

A peptide, obtained from T4 phage major capsid protein gP23 by chymotryptic digestion, has been shown to form two types of crystalline sheets, hexagonal and rectangular. The sheet peptide was subjected to conventional sequencing work. Together with the DNA sequence of gene 23, the results showed that the peptide consisted of 155 amino acids, located from 295 to 449 in the nascent gP23 and from 230 to 384 in the matured gP23.

Amino Acid Sequence↗
PubMed1984

Further studies on a rapid protein hydrolysis method.

Proteins may be hydrolysed for amino-acid analysis by a trifluoroacetic acid/HCl mixture at 166 degrees C for 25 or 50 min. A number of uncommon amino acids and certain amino-acid derivatives were subjected to this procedure and their decomposition rates were determined.

Amino Acids↗
PubMed1982

A new polyacrylamide gel electrophoresis system. Separation of small peptides and proteins in a volatile buffer system after modification with a strongly acidic fluorescent NH2 reagent.

Polyacrylamide gel electrophoresis is one of the most efficient methods for separation and identification of proteins. A new gel electrophoresis system has been developed in order to facilitate both separation and extraction of peptides and proteins ranging in molecular weight from approximately 200 up to 100 000. This system involves the use of a volatile buffer, triethylamine/formic acid pH 11.7, and a reaction with a covalently binding NH2 reagent, 1,3,6-trisulfonylpyrene 8-isothiocyanate. Under these conditions, the addition of strongly negative charges to proteins is achieved which allows migration according to molecular weight. The modified proteins being fluorescent require neither fixation nor staining for their detection. This is an absolute requirement especially when dealing with small peptides. An additional advantage of such a modification is the increased solubility of the proteins which makes their extraction easier and more efficient. THe extracted proteins are easily freed from salts and other small molecules simply by evaporation and they are readily available for sequencing analysis using Edman degradation, carboxypeptidase digestion or amino acid analysis.

Amines↗
PubMedDate not supplied

[Surgical case report: diagnosis of associated abdominal lesions in penetrating injuries of the lower chest].

We discuss the way to diagnose intra-abdominal lesions caused by penetrating objects in the lower thorax. Let us call these wounds penetrating wounds. Two kinds of penetrating wounds are considered: 1. shotwounds; 2. knifewounds. 1. In shotwounds of the lower thorax there is not any non-surgical method available to find the associated intra-abdominal lesions. In these cases the results of: 1. physical examination; 2. local wound exploration; 3. echography of the abdomen and 4. peritoneal lavage cannot be trusted. Only laparotomy can show us if any associated lesion in the abdomen exists. 2. For knifewounds we can make almost the same remarks: 1. physical examination; 2. local exploration of the lesion; 3. echography of the abdomen are not to be considered as good diagnostic tools to find the associated intra-abdominal wounds. However in this situation the results of peritoneal lavage are to be trusted. Without omitting a 24 h observation of the patient the most rational criteria for a positive peritoneal lavage are red blood cell greater than 100.000/mm3; white blood cell greater than 500/mm3.

Abdominal Injuries↗