Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
27
|
pubmed:dateCreated |
1986-4-7
|
pubmed:abstractText |
Purified bovine rhodopsin was reductively methylated with formaldehyde and pyridine/borane with the incorporation of approximately 20 methyl groups in the protein. Rhodopsin contains 10 non-active-site lysines, which account for the uptake of the 20 methyl groups. The permethylated rhodopsin thus formed is active toward bleaching, regeneration with 11-cis-retinal, and the activation of the GTPase (G protein) when photolyzed. The critical active-site lysine of permethylated rhodopsin can be liberated by photolysis. This lysine can be reductively methylated at 4 degrees C. Methylation under these conditions leads to the incorporations of approximately 1.5 methyl groups per opsin molecule using radioactive formaldehyde, with the ratio of epsilon-dimethyllysine:epsilon-monomethyllysine:lysine being approximately 5:4:1. The modified opsin(s) can regenerate with 11-cis-retinal to produce a mixture of active-site methylated and unmethylated rhodopsins having a lambda max = 512 nm. Using [14C]formaldehyde and [3H]retinal followed by reduction of the Schiff base, digestion, and chromatography showed that the active-site N-methyllysine was bound to the retinal. Treatment of the methylated opsin mixture (containing 1.5 active-site methyl groups) with o-phthalaldehyde/mercaptoethanol to functionalize the opsin bearing unreacted lysine, followed by regeneration with 11-cis-retinal and chromatographic separation, led to the preparation of the pure active-site epsilon-lysine monomethylated rhodopsin with a lambda max = 520 nm, significantly shifted bathochromically from rhodopsin or permethylated rhodopsin.(ABSTRACT TRUNCATED AT 250 WORDS)
|
pubmed:grant | |
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Formaldehyde,
http://linkedlifedata.com/resource/pubmed/chemical/Lysine,
http://linkedlifedata.com/resource/pubmed/chemical/Retinal Pigments,
http://linkedlifedata.com/resource/pubmed/chemical/Retinaldehyde,
http://linkedlifedata.com/resource/pubmed/chemical/Rhodopsin
|
pubmed:status |
MEDLINE
|
pubmed:month |
Dec
|
pubmed:issn |
0006-2960
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:day |
31
|
pubmed:volume |
24
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
8137-45
|
pubmed:dateRevised |
2008-11-21
|
pubmed:meshHeading |
pubmed-meshheading:3937555-Animals,
pubmed-meshheading:3937555-Binding Sites,
pubmed-meshheading:3937555-Cattle,
pubmed-meshheading:3937555-Formaldehyde,
pubmed-meshheading:3937555-Lysine,
pubmed-meshheading:3937555-Methylation,
pubmed-meshheading:3937555-Photoreceptor Cells,
pubmed-meshheading:3937555-Retinal Pigments,
pubmed-meshheading:3937555-Retinaldehyde,
pubmed-meshheading:3937555-Rhodopsin,
pubmed-meshheading:3937555-Rod Cell Outer Segment,
pubmed-meshheading:3937555-Spectrophotometry
|
pubmed:year |
1985
|
pubmed:articleTitle |
Methylation of the active-site lysine of rhodopsin.
|
pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|