Biomedical subjects

T Ikenaka

Publications and source records attributed to T Ikenaka.

At least 145 records · Page 8Linked to original sources

PubMed1976

Fragmentation of rat serum albumin by cyanogen bromide cleavage and the amino acid sequences of four fragments.

Rat serum albumin was cleaved into seven peptides by cyanogen bromide treatment followed by reduction and carboxymethylation. The amino acid composition and the N-terminus of each peptide and the amino acid sequences of four peptides were determined by conventional methods. An alignment of these peptides in the original protein was proposed in the light of the established sequences of bovine and human plasma albumin.

Amino Acid Sequence↗

PubMed1976

The amino acid sequences of two soybean double headed proteinase inhibitors and evolutionary consideration on the legume proteinase inhibitors.

Two proteinase inhibitors, C-II and D-II, were isolated from soybeans. C-II was shown to be an inhibitor of bovine trypsin [EC 3.4.21.4], bovine alpha-chymotrypsin [EC 3.4.21.1], and porcine elastase [EC 3.4.21.11], whereas D-II inhibited only trypsin. The complete amino acid sequences of the two inhibitors establishors. On the basis of the specificities of the inhibitors and their homologies with other double-headed inhibitors, the reactive sites of C-II seems to be alanine-22 for elastase and arginine-49 for trypsin (and probably also for chymotrypsin). D-II was quite unique because its both reactive sites are arginine residues and it only inhibits trypsin. It is suggested that D-II might be a primitive form of double-headed inhibitor and that the prototype single-headed inhibitor was a trypsin inhibitor with an arginine residue as the reactive site.

Amino Acid Sequence↗

PubMed1976

Comparative study of carbohydrate-protein complexes. II. Determination of hydroxylysine and its glycosides in human skin and scar collagens by an improved method.

A modification of the existing methods for measuring hydroxylysine, galactosylhydroxylysine, and glucosylgalactosylhydroxylysine is described. The method is based on analysis with an automated amino acid analyzer using a conventional separation system for basic amino acids. The prior removal of acidic and neutral amino acids was necessary. This was achieved by passing an alkaline hydrolysate of collagen through a column of Amberlite CG-120, Type II (H+) and washing the column with 8% aqueous pyridine. A basic fraction containing the hydroxylysine compounds was then recovered from the column by elution with 3 M NH4OH. Model experiments showed that hydroxylysine and its glycosides could be analyzed with an hour and that recoveries exceeded 90%. This method was applied to human tissues to investigate whether the dermal scar is different in collagen composition from normal skin. With the limited number of samples analyzed, the data suggested that long-standing scar tissues reverted to a composition similar to that of normal skin. The composition of hydroxylysine-linked carbohydrate units is also discussed on the basis of the age-related change.

Adolescent↗

PubMed1975

Beta-Elimination and sulfite addition reaction of chondroitin sulfate peptidoglycan and the peptide structure of the linkage region.

Pronase digestion of bovine tracheal cartilage yielded acid mucopolysaccharide - peptide complexes which were fractionated by chromatography on Dowex 1(C1-). A major fraction was eluted with 1.5 M NaC1 and presumed to by chondroitin sulfate A-peptidoglycan by cellulose acetate electrophoresis. Alkaline beta-elimination and sulfite addition reaction of this fraction yielded cysteic acid-containing peptides, two of which were obtained in an homogeneous state. The sequence determination of these two made it possible to remodel their original structures as Leu-Pro-Ser-Gly-Glu-Gly-Pro-Glu and Leu-Pro-Ser-Gly-Glu, where the serine residues carried polysaccharide chains. Together with the reported data on the polysaccharide-protein linkage region, the present result suggests that the -Ser-Gly- sequence is a minimum requisite for the glycosylation of serine residues in the protein core of various proteoglycans.

Amino Acid Sequence↗

PubMed1974