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Biomedical subjects

A Henschen

Publications and source records attributed to A Henschen.

At least 145 records · Page 8Linked to original sources
PubMed1979

Novel opioid peptides derived from casein (beta-casomorphins). I. Isolation from bovine casein peptone.

A material which displayed opioid activity in the guinea pig ileum longitudinal muscle-myenteric plexus preparation was extracted from an enzymatic casein digest into chloroform/methanol. The extract was roughly purified by adsorption/desorption procedures using charcoal and Amberlite XAD-2 resin as adsorbents. A high degree of purity was achieved by high-pressure liquid chromatography of the material on muBondapak C18 and mu-Porasil columns and finally by gel filtration chromatography on a Bio-Gel P-2 column. Several pronase-resistant compounds with opioid activity were obtained.

Animals↗
PubMed1979

Novel opioid peptides derived from casein (beta-casomorphins). II. Structure of active components from bovine casein peptone.

Material with opioid activity had been isolated from an enzymatic casein digest. It was shown to contain a pure heptapeptide with the sequence Tyr-Pro-Phe-Pro-Gly-Pro-Ile. The identity between the opioid principle and the peptide was proven by the fact that chemical reagents or enzymes effecting one would effect the other. After carboxypeptidase Y digestion a pentapeptide, Tyr-Pro-Phe-Pro-Gly, could be isolated; this peptide showed a higher opioid activity than the heptapeptide. The opioid peptides were highly resistant towards proteolysis, even by pronase. The sequence of the hepatapeptide identified it as a fragment of bovine beta-casein. Therefore it was named beta-casomorphin.

Amino Acid Sequence↗
PubMed1978

Structural relatedness of kappa-casein and fibrinogen gamma-chain.

kappa-Caseins, involved in the milk clotting process, and human fibrinogen gamma-chain, involved in the blood clotting process, show structural similarities. Several long kappa-casein sections, together corresponding to 80% of the whole protein molecule, have their counterparts in the gamma-chain of fibrinogen, in that 31--42% of the amino acid residues occupy identical positions. The section of kappa-casein which contains the chymosin-sensitive bond has a counterpart not only in the gamma but also in the Bbeta-chain of fibrinogen. Furthermore, the secondary structures of the kappa-caseins and of the gamma-chain predicted according to the method of Chou and Fasman present several common features.

Amino Acid Sequence↗
PubMed1978

Disulfide bridges in the middle part of human fibrinogen.

Human fibrinogen contains 29 disulfide bridges per molecule. The amino acid sequences around all half-cystine residues are known. When fibrinogen is cleaved by cyanogen bromide five disulfide-containing fragments are formed. The second-largest of them is derived from the middle part of all three peptide chains, it is monomeric and contains 345 amino acid residues, 12 of which are half-cystines. The arrangement of the six disulfide bonds was determined by analysing sequences and amino acid compositions of subfragments isolated after cleavage with trypsin, thermolysin and staphylococcal protease and after clearage of the disulfide bonds. All half-cystine residues were found to be linked in unique pairs. Six half-cystine residues, two in each of the three peptide chains and forming the -Cys-X-X-X-Cys- sequences, were shown to connect the chains in a ring-like structure, similar to the one in the N-terminal part of the molecule. The remaining six half-cystine residues were found to connect two sections of the gamma-chain in a loop-like structure and four sections of the beta-chain in a loop-inside-a-loop-like structure, the inner beta-chain loop being homologous to the gamma-chain loop.

Amino Acid Sequence↗