Binding of photosensitizing dyes with some biopolymers.

To obtain some information of the biological action of Kankohso 101dinicotinate and Kankohso 301-nicotinate, observations were made on the binding mode of these substances with protein, chondroitin sulfate and nucleic acids and the following results were obtained; 1. Kankohso 10 I-dinicotinate binds reversively with bovine serum albumin or serum r-globulin, resulting in metachromasia. By binding with proteins the absorption maximum of the dye shifts toward the long wave length side and the absorbance decreased distinctly. The data show that there are more than one kind of binding sites and the binding with bovine serum albumin is weak in acidic solution and strong in alkaline solution. 2. Kankohso 10 I-dinicotinate produces strong metachromasia with sodium chondroitin sulfate and the color of the solution changes from violet blue to reddish violet. The absorption maximum at 592 mp. decreases without shifting its wave length ,and the shoulder appears at 555 mp. be. comes distinct peak. The strongest metachromatical changes occurs at the concentration of the chondroitinsulfate whose sulfonate radicals is equal to the molecules of Kankohso 10 I-dinicotinate. 3. Kankohso IOI-dinicotinate produces metachromasia with nucleic acid, where absorption spectrum is shifted toward long wave length and absorbance is decreased at a certain concentration. 4. Kankohso 301.nicotinate binds weakly with bovine serum albumin, the binding of which is reversible and the maximum binding number is 1.1 per molecule of albumin. Metachromasia cannot be produced by binding. Kankohso 30I.nicotinate does not bind with bovine serum γ-globulin. This compund does not produce metachromasia with sodium chondroitin sulfate but produces weak metachromasia with nucleic acid, indicating some affinity to nucleic acid. ∗PMID: 4195456 [PubMed indexed for MEDLINE] Copyright c ©OKAYAMA UNIVERSITY MEDICAL SCHOOL Acta Merl. Okayama 24, 185-204 (1970) BINDING OF PHOTOSENSITIZING DYES WITH SOME BIOPOLYMERS