Photooxidation of bovine insulin sensitized by methylene blue

Weil, L.; Seibles, Thomas S.; Herskovits, Theodore T.

doi:10.1016/0003-9861(65)90191-8

Cited by 77 publications

(15 citation statements)

References 25 publications

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“…[37][38][39][40][41][42][43][44][45] Previously, photooxidation was used to study protein function through amino acid alterations. [46][47][48][49][50][51][52][53][54][55][56] The discovery that photooxidation could stabilize a protein solution 56 led to the development of this technology for biomedical purposes. The process was found to yield a biomaterial possessing many favorable properties for long-term implantable medical devices.…”

Section: Introductionmentioning

confidence: 99%

Calcification resistance, biostability, and low immunogenic potential of porcine heart valves modified by dye-mediated photooxidation

Moore

Adams

2001

J. Biomed. Mater. Res.

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The calcification potential, biostability, and immunogenic response of materials intended for long-term in vivo use, such as in heart-valve bioprostheses, are essential components of device performance. Here we explore these properties in photooxidized porcine heart valves. To study immunological sensitization, we injected tissue extracts intradermally into guinea pigs. Test and control animals received a challenge patch of the appropriate extract and were scored for dermal reactions. Neither cottonseed oil nor sodium chloride extracts of photooxidized heart-valve tissues caused any dermal inflammatory response. After implantation in the rat subcutaneous model for 90 days, the calcium content of 48-h-treated photooxidized cusp tissue [0.04 +/- 0.00 mg/g wet weight (gww)] was comparable to that of unimplanted control tissues (usually <1 mg/gww) and much lower than that of glutaraldehyde-treated controls (71 +/- 15 mg/gww). The porcine aortic wall calcium content (49 +/- 31 mg/gww) was comparable to that of glutaraldehyde-treated controls (59 +/- 8 mg/gww). Histologically, a time-dependent decrease in inflammation and vascularization with increasing photooxidation time was noted in the rat model along with an increase in the stability and organization of collagen bundles. In summary, porcine valve tissues treated by dye-mediated photooxidation were resistant to calcification, were biostable, and demonstrated a low immunogenic response, indicating potential for use in heart-valve bioprostheses.

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Section: Introductionmentioning

confidence: 99%

Calcification resistance, biostability, and low immunogenic potential of porcine heart valves modified by dye-mediated photooxidation

Moore

Adams

2001

J. Biomed. Mater. Res.

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“…Bovine insulin (bINS; MW 5734 Da; Weil et al, 1965) was used as received from Sigma (catalog No. I-5500).…”

Section: Methodsmentioning

confidence: 99%

Trace fluorescent labeling for high-throughput crystallography

Forsythe¹,

Achari²,

Pusey³

2006

Acta Crystallogr D Biol Cryst

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Covalent labeling of macromolecules with trace levels (<1%) of a fluorescent dye is proposed as a means to facilitate finding or detecting crystals in crystallization drops. To test the effects of labeled protein concentration on the resulting X-ray diffraction data, experiments were carried out with the model proteins insulin, ribonuclease, lysozyme and thaumatin, which were labeled with the fluorescent dye carboxyrhodamine. All proteins were labeled on their N-terminal amine and lysozyme was also labeled randomly on lysine side chains in a separate series of experiments. Ribonuclease and N-terminal amine-labeled lysozyme crystals were poorly formed at 10% label concentration and these were not used in subsequent diffraction experiments. All model proteins were tested to 5% labeled protein, and thaumatin and randomly labeled lysozyme gave well formed crystals to 10% labeled protein. In all cases tested, the presence of the label was found to not significantly affect the X-ray diffraction data quality obtained. Qualitative visual-inspection experiments over a range of label concentrations indicated that optimum derivatization levels ranged from 0.025-0.05% for insulin to 0.1-0.25% for thaumatin. Light intensity is a simpler search parameter than straight lines and by virtue of being the most densely packed phase, labeled crystals should be the most intense light sources under fluorescent illumination. For both visual and automated methods of crystal detection, label intensity is a simpler and potentially more powerful search parameter. Screening experiments using the proteins canavalin, beta-lactoglobulins A and B and chymotrypsinogen, all at 0.5% label concentration, demonstrated the utility of this approach to rapidly finding crystals, even when obscured by precipitate. The use of trace-labeled protein is also proposed to be useful for the automated centering of crystals in X-ray beamlines.

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“…This is not opposed to what has been discussed in relation to tryptophan since the residues of this amino acid, which have been assigned as shielded, are in areas completely different to the region in which Tyr-20 and Tyr-23 residues are found. Weil et al (1965) have reported that in insulin there is an additional photo-oxidation of Tyr residues, when this is subjected to the action of 8 M urea or by raising the temperature prior to illumination.…”

Section: T/t 0 = Fle-klt+f2 E-k2tmentioning

confidence: 97%

Isolation and photo-oxidation of lysozyme fragments

Ferrer

Silva

1981

Radiat Environ Biophys

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Reduction of the four disulfide bonds and further carboxymethylation of lysozyme followed by its reaction with CNBr brings about L-I, (aa 1-12) and L-II-III (aa 13-129) peptides. When breaking the polypeptidic chain by CNBr action and freeing the peptides formed through S-S bonds reduction and carboxymethylation three peptides are obtained corresponding to L-I (aa 1-12), L-II (aa 13-105) and L-III (aa 106-129). L-II-III, L-III and L-II peptides were separately subjected to photo-oxidation in presence of riboflavin, in 0.05 M phosphate buffer, pH 7.0. The kinetic analysis of Trp photo-oxidation in L-II-III peptides shows that these residues keep, to a great extent, the degree of exposition they had in native lysozyme. L-II peptide also presents Trp residues with a different degree of exposition. Presence of Tyr photo-oxidation in L-II and L-II-III peptides - what does not take place in native lysozyme - suggests a relationship between photo-oxidation selectivity and the degree of exposition of certain amino acid residues in spatial configuration.

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Photooxidation of bovine insulin sensitized by methylene blue

Cited by 77 publications

References 25 publications

Calcification resistance, biostability, and low immunogenic potential of porcine heart valves modified by dye-mediated photooxidation

Calcification resistance, biostability, and low immunogenic potential of porcine heart valves modified by dye-mediated photooxidation

Trace fluorescent labeling for high-throughput crystallography

Isolation and photo-oxidation of lysozyme fragments

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