ASSOCIATION BETWEEN AMINO ACID SEQUENCES IN PEPTIDE BINDING REGION (BOLA-DRB3) AND SUSCEPTIBILITY OR RESISTANCE TO CALF DIARRHEA

Nikbakhat, Gholamraza; Tajbakhsh, Hasan; Mokhber Dezfooli, Mohammadreza; Zahrai Salehi, Taghi; Rabani, Mohammad; Gharibi, Daruosh; Emam, Seyed Mehdi; Asadiyan, Farzaneh; Khormali, Mahmood

ASSOCIATION BETWEEN AMINO ACID SEQUENCES IN PEPTIDE BINDING REGION (BOLA-DRB3) AND SUSCEPTIBILITY OR RESISTANCE TO CALF DIARRHEA

Authors

gholamraza nikbakhat

Hasan Tajbakhsh

Mohammadreza Mokhber dezfooli

Taghi Zahrai salehi

Mohammad Rabani

Daruosh Gharibi

Seyed Mehdi Emam

Farzaneh Asadiyan

Mahmood Khormali

Abstract

The major histocompatibility complex genes (mhc) encode MHC I and II molecules which present peptide fragments to T cells. Therefore these polymorphic molecules critically influence susceptibility to infectious diseases. At present study potential relationship between amino acid sequences in the antigen binding groove of different BoLA-DRB3 alleles and susceptibility or resistance to calf diarrhea was investigated. Twelve different DRB3 alleles were found among 171 calves (84 diarrheic and 87 healthy) analyesd by PCR-RFLP method. Amino acid sequences of the encoded peptide binding region were compared. 26 polymorphic positions were detected in this region. A significant association (p< 0.05) was shown between occurrence of diarrhea and the presence of glutamic acid and tyrosine in pocket 4 and valine, glutamine and leucine in pocket 9 of peptide binding region. Thus it can be concluded that pockets 4 and 9 of the BoLA-DRB3 molecule would be involved in conferring susceptibility of calf to diarrhea.

Keywords

BoLA-DRB3

calf diarrhea

MHC

PCR-RFLP

peptide binding region.