Poster presentation
192
PEPTIDES OF THE THYMOPTIN
U.J. Ishimov
1,2
, Sh.S. Olimjonov
1
, A.M. Ne’matova
2
, J.F. Ziyavitdinov
1
1) Institute of Bioorganic Chemistry, Academy of Sciences Republic of Uzbekistan,
Tashkent
2) Tashkent chemical technological institute Republic of Uzbekistan, Tashkent.
e-mail: uchkunishimov@gmail.com
Currently, one of the priority areas in the development
of effective drugs is the
search and isolation of biologically active substances, in particular, of a protein-peptide
nature, acting in extremely low concentrations.
Thymoptin, widely used to correct human immunity, consists of a mixture of acidic
peptides isolated from the thymus of lambs or calves. The main thymoptin peptide, α1-
thymosin, consists of 28 amino acid residues and has an MM of 3065 Da. Another high-
abundant, β4 - thymosin, consists of 43 amino acid residues has an MM of 4982 Da.
Thymopoetin consisting of 49 amino acid residues has an MM of 5561 Da.
To carry
out thymoptin peptide mapping, the substance was fractionated by RP-
HPLC on an Agilent Technologies 1200 instrument (USA) using a Nucleosil 5 C
18
column (4.6 mm x 250 mm) in the isocratic mode of 97% acetonitrile in water. As a
result, 6 individual peptides
were obtained, which were eluted from the column in the
time interval of 2-6 min.
The molecular weight of major peptides with retention times in the column of 2.54
(I), 2.71 (II), and 5.75 (III) min was determined on an Agilent Technologies 6530B
Chip-HPLC-Q-TOF mass spectrometer. The molecular ion of the peptide - I was found
at m/z 3065.5008, the peptide - II m/z 4919.4830, and the peptide - III m/z 5561.956.
After trypsinolysis, MS/MS analyzes were performed and the exact molecular masses of
fragment and daughter ions were determined. The
obtained mass spectra were
interpreted using the Mass COT and Spectrum Mill programs. As a result of the
chromato-mass-spectrometric studies, the following
fragmentary peptides were
established: for peptide I with m/z: EVVEEAEN – 917.3978, SDAAVDTSSEITTK –
1406.6645, EKK – 385.2325, DLK– 356.206;
For peptide II with m/z: PDMAEIEK -913.4215, FDKSK- 605.3173, SDK -
331.1612, ETIEQEK– 857.4131, LKK – 369.274, NPLPSK – 636.3595, TETQEK –
716.3341, QAGES–490, 2023;
For
peptide
III
with
m/z:
SQLVANNVTLPAGEQRK–1824.9926,
SQFLEDPSVLTK–1363.7104,
DVYVQLYLGTLTAVKR–1839.0375,
GKLK–
445.3133.
Using the Blast database, the complete primary structure and the name of the isolated
major peptides of the Timoptin substance were established:
Peptide I – SDAAVDTSSEITTKDLKEKKEVVEEAEN – α1 - thymosin.
Peptide II – SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES –
β4 - thymosin.
Peptide III -
SQFLEDPSVLTKGKLKSQLVANNVTLPAGEQRKDVYVQLYLGTLT-
AVKRThymopoietin.