Adenosine receptor stability is because of extensive disulfide bonds formed between:: (A) Cysteine, (B) Methionine, (C) Arginine, (D) Alanine
Answer is A. Disulfide bonds can only be formed between one amino acid i.e. cysteine, as it has sulfhydryl group (-SH). Two cysteine gets joined to form cystine (having disulfide bond) (see fig). It a strong covalent bond.