Selective Cleavage of C-Tryptophyl Peptide Bonds in Proteins and Peptides

Ramachandran, L. K.; Witkop, Bernhard

doi:10.1021/ja01524a053

Cited by 81 publications

(19 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Tyro-sine-2 is slowly available for reaction, while tyrosines-70 and 72 are unreactive. None of the three tryptophan residues is available in the virus either for reaction [42,43] or for interaction with the solvent [44], but residues 17 and 52 become available upon dissociation of the protein.…”

Section: Surface Availability Of Residuesmentioning

confidence: 99%

A Prediction of the Structure of Tobacco-Mosaic-Virus Protein

Durham

Butler

1975

Eur J Biochem

View full text Add to dashboard Cite

The location of amino acid residues within the tobacco mosaic virus protein subunit is discussed. Sequence data, X-ray crystallographic measurements, and the availability of specific residues for enzymic, immunological or chemical reaction are amongst the information used to trace roughly how the tobacco mosaic virus polypeptide chain winds in and out from the virus axis. Published rules for predicting secondary structure are then applied to obtain a diagram of the course of the polypeptide chain. This map should be useful for the interpretation of X-ray diffraction data and already permits an outline of the main features of the inner third of subunit to be suggested.Tobacco mosaic virus (TMV) protein presents a difficult problem for X-ray crystallographic structure determination. It can be crystallised as disks [1,2] but the asymmetric unit is very large (about 600000 daltons) and oriented gels of the virus itself are not sufficiently ordered to yield information to atomic resolution. Therefore, as an aid to the interpretation of current X-ray results, we attempt here to make deductions about the structure of the protein subunit from other available evidence. Such deductions impose limitations on the range of interactions between amino acid residues that may be proposed to explain other experimental data and, of course, the work also represents an exploration of the current state of the art of protein structure prediction.TMV protein is an unusually favourable subject for structure prediction because so much is already known about it. The information summarised here was obtained by many methods, the most important of which is X-ray crystallography, but also including electron microscopy, amino acid sequencing, titration studies and studies of the chemical, enzymic and immunological reactivity of various amino acid residues. The secondary structure of the polypeptide chain is then predicted, using the rules of Chou and Fasman [3,4]. Together these results enable us to propose a diagram of the approximate path of the polypeptide chain. Earlier attempts at partial TMV protein structure prediction have been made by Schiffer and Edmundson [5], and Leberman [7]. We gladly acknowledge that our thinking is based upon the labours of many people, not always explicitly mentioned here. In particular we acknowledge our debt to the crystallographic studies of Dr K. C. Holmes and his colleagues, started in Cambridge and continued, more recently, in Heidelberg. Low-Resolution Structural InformationThe TMV protein subunit contains 158 amino acid residues and has a molecular weight of 17493 [8,9]. Electron microscope and X-ray studies upon the virus (reviewed by Klug and Caspar [lo] and more recently by Barrett et al. [ll]) show that each subunit can be contained within a sector-shaped domain, like a slice of cake, within an angle of about 22". It extends radially from about 20 8, to about 90 8, from the virus helix axis, and is about 25 8, high. The RNA fits between the protein subunits in a groove at a radius of about 40 A,...

show abstract

Section: Surface Availability Of Residuesmentioning

confidence: 99%

A Prediction of the Structure of Tobacco-Mosaic-Virus Protein

Durham

Butler

1975

Eur J Biochem

View full text Add to dashboard Cite

show abstract

“…Highly purified ovine and porcine ACTH were isolated as previously described 0367-8377/80/050480-05 $02.00/0 0 1980 Munksgaard, Copenhagen (Pickering et al, 1963;Canova-Davis & Ramachandran, 1976). Synthetic human ACTH (Yamashiro & Li, 1973), [3,[5][6][7][8][9][10][11][12] ] TyrZ-ACTH [3,5-12] Tyr23 -ACTH, [3,5-Iz] T J '~~'~~-A C T H (Lemaire et al, 1977), a~-38ACT€l (Li et a l , 1978), a;-%ACTH (Ramachandran & Li, 1965), Ala1a'-20NH2 ACTH(Blake& Li, 1974), CY'-'~ACTH (Li et al, 1964a), a'"'ACTH (Li et al, 1964b) and monkey fl-MSH p a n g et al., 1973) were all synthesized in this laboratory and generously provided by Professor C.H. Li.…”

Section: Methodsmentioning

confidence: 99%

Immunochemical Studies of Adrenocorticotropin Using Tritium Labeled Hormone

Rao

Behrens

Ramachandran

1980

International Journal of Peptide and Protein Research

View full text Add to dashboard Cite

A radioimmunoassay using specifically tritiated corticotropin (3H‐ACTH) of high specific radioactivity (46 Ci/mmol) and full biological activity has been developed. The assay is sensitive to ACTH in the range 200 pg‐10 ng. 50% displacement of 3H‐ACTH is produced by less than a twofold excess of unlabeled hormone. Immunochemical studies with various ACTH analogs showed that the antiserum recognized the intact molecule better than any of the fragments.

show abstract

“…NBS has been developed as a reagent for specific cleavage of tryptophyl and tyrosyl peptide bonds (Ramachandran & Witkop 1959, Patchornik, Lawson, Gross & Witkop 1960, Schmir, Cohen & Witkop 1959, and there was some possibility of cleavage at a tryptophyl and/or tyrosyl bonds in RNase TI. Such a cleavage at the tryptophylprolyl bond (59-60) in RNase T1 will result in formation of two peptide chains, one acidic and the other less acidic.…”

Section: Figurementioning

confidence: 99%

THE OXIDATION WITH N‐BROMOSUCCINIMIDE OF THE SINGLE TRYPTOPHAN RESIDUE IN RIBONUCLEASE T₁

Kawashima

Ando

1969

International Journal of Protein Research

View full text Add to dashboard Cite

1. The single tryptophan residue‐59 present in RNase T1 was oxidized almost specifically by NBS in 8 M urea. The enzymatic activity of RNase T1 decreased with the increase in the amount of NBS used, and complete inactivation took place within 10 minutes when 2 equivalents of the reagent were used. 2. During the oxidation with NBS of RNase T1 no cleavage of peptide bonds was found and none of the amino acid residues other than tryptophan was affected except for oxidation of cystine to cysteic acid in a small amount (up to 20 %). The complete inactivation of the enzyme occurred when the tryptophan residue was completely oxidized. 3. The oxidized RNase T1 possessed a lower solubility than the native enzyme. Measurements of the optical rotatory dispersion and the circular dichroism indicated the occurrence, of some but not so great conformational changes in the enzyme by the oxidation. 4. These residts clearly demonstrated the importance of the single tryptophan residue in RNase T1 for the proper function of the enzyme.

show abstract

Selective Cleavage of C-Tryptophyl Peptide Bonds in Proteins and Peptides

Cited by 81 publications

References 0 publications

A Prediction of the Structure of Tobacco-Mosaic-Virus Protein

A Prediction of the Structure of Tobacco-Mosaic-Virus Protein

Immunochemical Studies of Adrenocorticotropin Using Tritium Labeled Hormone

THE OXIDATION WITH N‐BROMOSUCCINIMIDE OF THE SINGLE TRYPTOPHAN RESIDUE IN RIBONUCLEASE T₁

Contact Info

Product

Resources

About

Selective Cleavage of C-Tryptophyl Peptide Bonds in Proteins and Peptides

Cited by 81 publications

References 0 publications

A Prediction of the Structure of Tobacco-Mosaic-Virus Protein

A Prediction of the Structure of Tobacco-Mosaic-Virus Protein

Immunochemical Studies of Adrenocorticotropin Using Tritium Labeled Hormone

THE OXIDATION WITH N‐BROMOSUCCINIMIDE OF THE SINGLE TRYPTOPHAN RESIDUE IN RIBONUCLEASE T1

Contact Info

Product

Resources

About

THE OXIDATION WITH N‐BROMOSUCCINIMIDE OF THE SINGLE TRYPTOPHAN RESIDUE IN RIBONUCLEASE T₁