Homework Solution: It is possible to make some predictions about protein secondary structure based…

    It is possible to make some predictions about protein secondary structure based on the primary sequence. Consider the following amino acid sequence: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Ile-Ala-His-Thr-Tyr-Gly-Pro-Phe-Glu-Ala-Ala-Met-Cys-Lys-Trp-Glu-Ala-Gln-Pro-Asp-Gly-Met-Glu-Cys-Ala-Phe-His-Arg A) Where might Beta-Turns occur? B) Where might intrachain disulfide cross-linkages be formed? C) Assuming that this sequence is part of a larger globular protein, what is the probable location (exterior or interior of the protein) of the amino acid residues: Asp Ile Thr Ala Gln Lys Explain your reasoning.

    Expert Answer

    Answer:

    It is potential to form some predictions environing protein unimportant construction fixed on the chief aftercited. Consider the aftercited amino shrill aftercited:

    1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

    Ile-Ala-His-Thr-Tyr-Gly-Pro-Phe-Glu-Ala-Ala-Met-Cys-Lys-Trp-Glu-Ala-Gln-Pro-Asp-Gly-Met-Glu-Cys-Ala-Phe-His-Arg

    A) Where jurisdiction Beta-Turns betide?

    B) Where jurisdiction intrachain disulfide cantankerous-linkages be formed?

    C) Assuming that this aftercited is bisect of a larger smooth protein, what is the reasonable residuum (outer or internal of the protein) of the amino shrill residues:

    Asp Ile Thr Ala Gln Lys

    Explain your forced.

    Expert Retort

    Answer:

    A. Beta turns are linked with Prolines having the cyclic construction which are bestow at 7th and 19th position. These cyclic constructions are good-tempered-tempered in tidings of bends internally the protein construction.

    B. Disulfide cantankerous stringing ground at cysteines residues which are bestow at 13th and 24th position. Cysteine residues accept thiol groups which aid in tie shape.

    C. Polar amino shrill dispose them wilful at the without residuum and Non-Polar amino shrill succeed dispose themselves at internally of the protein construction. Polar amino shrills are Asp, Gln, and Lys, Non Polar amino shrills are Ala and Ile. “Thr” accept the middle polarity which can be ground at the either cause.