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G E PERLMANN

Publications and source records attributed to G E PERLMANN.

At least 19 recordsLinked to original sources
PubMed1959

The amino acid composition of crystalline pepsin.

The amino acid composition of twice recrystallized pepsin (Worthington Biochemical Corporation) has been determined chromatographically on columns of Amberlite IR 120 resin. The results of the analyses obtained on four different preparations indicate a close agreement in their amino acid composition. Pepsin is unique in that it has a great predominance of acidic amino acids over basic ones. Moreover, all the preparations contain a small and constant amount of hydroxyproline, corresponding to about 0.1 residue per molecule.

Amino Acid Sequence↗
PubMed1959

Ultraviolet difference spectra of pepsin.

A shift of pH of pepsin solutions from 4.6 to 1.0 gives rise to spectral displacements in the ultraviolet. If represented as difference spectra three peaks with maxima at 2770, 2850, and 2930 Angströms are present which can be attributed to the tyrosine and tryptophan residues in the protein. On mild autolysis of pepsin at pH 2.0 the absorbancy in the ultraviolet further decreases. Although some of these effects can be ascribed to the occurrence of hydrogen bonding between the aromatic residues and a carboxylate ion, those observed on autolysis are caused by charge effects of newly formed polar groups in the vicinity of a chromophore. No direct relation between the optical properties described here and enzymic activity of pepsin has been observed.

Hydrogen Bonding↗
PubMed1958

Enzymic dephosphorylation of pepsin and pepsinogen.

It has been shown by the work presented in this paper that it is possible to dephosphorylate enzymically pepsin and pepsinogen with a variety of phosphatases. With the aid of a phosphodiesterase and the prostate phosphatase it has been established that the phosphorus in the two proteins is present as a diester and connects two sites of the peptide chain in a cyclic configuration. Removal of the phosphorus does not affect the proteolytic activity against hemoglobin or the synthetic substrate acetyl-L-phenylalanyl diiodotryosine, nor the pepsinogen pepsin transformation. However, an increase of the autodigestion of pepsin is observed.

Enzyme Precursors↗
PubMed1952

Preparation and properties of type-specific M antigen isolated from a group A, type 1 hemolytic streptococcus.

Type-specific M antigen was extracted by heating type 1 group A streptococci at pH 2 in a boiling water bath. The protein was then purified by digestion with a preparation of crystalline ribonuclease which was free of proteolytic activity. It was further purified by fractional precipitation with (NH(4))(2)SO(4). Elementary chemical analysis of the preparation thus obtained showed an absence of phosphorus and a sulfur content of 2.46 per cent. In the ultraviolet the maximum absorption was at a wave length of 276 mmicro and the minimum at 255 mmicro. In electrophoresis experiments the preparation showed a single peak in the pH range of 3 to 9, but considerable boundary spreading was observed. The type 1 M antigen was isoelectric at pH 5.3 in sodium acetate buffer of ionic strength 0.1. The serological reactivity of the protein isolated was typical of type 1 M antigen. This protein induced the formation in rabbits of type-specific precipitins and protective antibodies. The absorption of type 1 antibacterial serum with the purified M antigen removed both the protective antibodies and the type-specific precipitins from the serum.

Antibodies↗